Basic Science and Sructure of Skin MCQs

8/11/2019 Basic Science and Sructure of Skin MCQs

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Desmoglein 1 is the antigen in which of the following autoimmune diseases of the skin:

1 Pemphigus foliaceus

2 Bullous impetigo

3 Dermatitis herpetiformis

4 Bullous pemphigoid

5 Pemphigoid gestationis

Q/Q(M)-482410 Report a Problem

Desmoglein 1 is the antigen in which of the following autoimmune diseases of the skin:

1 Pemphigus foliaceus

The antigen implicated in pemphigus foliaceus is Desmoglein 1. Desmoglein 1 is targeted in bullousimpetigo, but this is an infectious condition, not an autoimmune disease. The antigen in dermatitisherpetiformis is transglutaminase 3. The antigens for both bullous pemphigoid and pemphigoid

gestationis are BPAG1 and BPAG2.Q/Q(M)-482410 Report a Problem

What is the major component of the anchoring fibril?

1 Type I Collagen

2 Type III Collagen

3 Type IV Collagen

4 Type VII Collagen

5 Laminin 5


What is the major component of the anchoring fibril?

4 Type VII Collagen

Anchoring fibrils are made of Type VII collegen. Anchoring plaques are made of Type IV collagen,and interact with a network of Type I And Type III collagen fibers in the dermis.


Red or blonde hair pigmentation primarily results from:

1 The presence of eumelanin

2 The absence of melanin

3 The presence of pheomelanin

4 The reduced activity of tyrosinase

5 The reduced activity of DOPA dehydroxylase



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Red or blonde hair pigmentation primarily results from:

3 The presence of pheomelanin

Hair color is determined by melanocytes. The melanocytic activity of follicular melanocytes iscoupled to anagenhair is only pigmented when it is growing. Pigment is produced in the matrixarea of follicle, above the follicular papilla. Eumelanin is the pigment of brown/black hairs, and

pheomelanin is the pigment of red/blonde hairs. Intensity of color is proportional to the amount ofpigment. The absence of pigment produces white hair, and markedly reduced pigment produces grayhair.


Which of the following is true in or associated with Apert Syndrome?

1 Secondary to a mutation in FGFR3

2 AR

3 Acne localized to buttocks and thighs4 Cutaneous/ocular depigmentation

5 Synostoses


Which of the following is true in or associated with Apert Syndrome?

5 Synostoses

Apert Syndrome is an AD syndrome secondary to a mutation in FGFR2. Also known as

acrocephlosyndactyly, this condition includes synostoses of the hands, feet, back and skull as well asgeneralized acne. Mosaicism of this gene causes nevus comedonicus. There is associated cutaneousand ocular hypopigmentation.


Darier's sign is described as:

1 When an intact epidermis shears away from the underlying dermis, leaving a moist surface

2 Spreading bulla phenomenon with pressure on an intact bulla

3 Swollen, itchy and or red after stroking the skin

4 Central depression within a lesion when squeezed along its margins

5 Disappearance of color when the lesion is pressed


Darier's sign is described as:


Swollen, itchy and or red after stroking the skin is referred to Darier's sign and can be seen in systemicmastocytosis or urticaria pigmentosa. Nikolsky sign can be seen when an intact epidermis shears awayfrom the underlying dermis, leaving a moist surface (seen in pemphigus vulgaris, staphylococcus


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scalded skin syndrome (SSSS), and toxic epidermal necrosis). Spreading bulla phenomenon withpressure on an intact bulla is referred to as Asboe-Hansen sign, commonly seen with pemphigusvulgaris. Central depression within a lesion when squeezed is referred to as the dimpling sign and isseen in dermatofibromas. Disappearance of color or blanching when the lesion is pressed is commonlyfound on vascular lesions


A salt split skin DIF is performed on a biopsy taken adjacent to the skin lesions shown. Where wouldyou expect staining to be seen?

1 Epidermal side

2 Dermal side

3 Epidermal and Dermal sides equally

4 In the lamina densa

5 In the anchoring plaques


A salt split skin DIF is performed on a biopsy taken adjacent to the skin lesions shown. Where wouldyou expect staining to be seen?

1 Epidermal side

The image shown is bullous pemphigoid. On salt split skin DIF exams, deposits are seen on theepidermal side of the split. If dermal deposits are seen, epidermolysis bullosa acquisita or anti-epiligrin

pemphigoid are potential diagnoses.


During hair follicle development, the WNT signaling pathway is one of the earliest molecularpathways involved in hair follicle initiation. What is the downstream mediator of WNT signaling?

1 Smoothened

2 Beta-catenin

3 Keratin 16

4 p53

5 HLA-B27



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During hair follicle development, the WNT signaling pathway is one of the earliest molecularpathways involved in hair follicle initiation. What is the downstream mediator of WNT signaling?

2 Beta-catenin

Beta-catenin is the downstream mediator of WNT signaling. Through a series of signals, WNTproteins inhibit the degradation of beta-catenin in the cytoplasm. After being translocated to thenucleus, beta-catenin then forms a complex with LEF/TCF transcription factors, which ultimately

results in expression of downstream genes. Activation of this pathway is necessary for epithelium tohave the potential to develop a hair follicle.


Which of the following glands is not under neural control?

1 Sebaceous glands

2 Apocrine glands

3 Eccrine glands

4 Salivary glands

5 Ceruminous glands


Which of the following glands is not under neural control?

1 Sebaceous glands

Sebum is secreted continuously on the skin under hormonal glands. It contains squalene, cholesterol,cholesterol esters, wax, and triglycerides.


Regarding dermal-epidermal junction, which of the following statements is true:

1 There are no anchoring filaments in lamina lucida

2 Lamina fibroreticularis lies above lamina densa

3 Lamina fibroreticularis comprises of anchoring fibrils and the elastic microfibrils

4 Blood vessels cross the dermal-epidermal junction to reach the epidermis

5 Lamina lucida is an electron-dense layerQ/Q(M)-481901 Report a Problem

Regarding dermal-epidermal junction, which of the following statements is true:

3 Lamina fibroreticularis comprises of anchoring fibrils and the elastic microfibrils

Lamina fibroreticularis comprises of anchoring fibrils and the elastic microfibrils. Laminafibroreticularis lies below lamina densa. Blood vessels don't cross the dermal-epidermal junction toreach the epidermis. Basement membrane contain both: 1)Lamina basale which include a.lamina

lucida and b.lamina densa( which contain collagene IV & other glycoproteins like laminins,fibronectinetc.) 2)Lamina fibroreticularis contain collagen type III and anchoring fibrils (collagen type VII)



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In the epidermis, the cell most responsible for antigen detection and processing is the:

1 Keratinocytes

2 Merkel Cell

3 Melanocyte

4 Langerhans cell

5 CD4+ T cell


In the epidermis, the cell most responsible for antigen detection and processing is the:

4 Langerhans cell

The Langerhans cell is a bone narrow-derived, antigen-presenting cell found in all layers of the

epidermis, oral mucosa, esophagus, and vagina. Langerhans cells ingest and process antigens, mature,migrate to a local lymph node, and then present the antigen to a nave (or resting) T cell, activatingthat T cell. The Langerhans cell is central to the pathogenesis of atopic dermatitis, psoriasis, allergiccontact dermatitis, and certain infections, such as Leishmaniasis.


What is the significance of the critical line of Auber?

1 It is the location of the insertion of the erector pili muscle

2 the bulk of the mitotic activity in the hair occurs above this line

3 the inner root sheath is formed above this line

4 It is the widest diameter of the hair bulb

5 It is where keratinization first occurs in the hair


What is the significance of the critical line of Auber?

4 It is the widest diameter of the hair bulb

The critical line of Auber is at the widest diameter fo the hair bulb. Below this line, the bulk of mitoticactivity that gives rise to the hair and the inner root sheath occurs. The erector pili muscle inserts in theisthmus region of the follicle. Keratinization first occurs above this line.


The finding on DIF that reflects binding of the Ro and La antigens in subacute cutaneous lupuserythematosus is:

1 Granular fluorescence throughout the cytoplasm and nucleus of basal keratinocytes

2 Cytoid bodies3 Immune deposits along the DE junction


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4 Granular deposits along the basement membrane

5 A "chicken-wire" pattern within the epidermis


The finding on DIF that reflects binding of the Ro and La antigens in subacute cutaneous lupus

erythematosus is:

1 Granular fluorescence throughout the cytoplasm and nucleus of basal keratinocytes

Granular fluorescence throughout the cytoplasm and nucleus of basal keratinocytes reflect the bindingof Ro and La antigens and is unique to SCLE. Cytoid bodies and Immune deposits along dermal-epidermal junction are seen in both DLE and SCLE. Granular deposits along the basement membraneare seen in dermatitis herpetiformis and a chicken-wire pattern of staining is seen in pemphigusvulgaris.


Glomus cells are primarily found:

1 on hands/feet

2 on the trunk

3 on the lateral thighs

4 on the genital skin

5 on the face


Glomus cells are primarily found:

1 on hands/feet

Glomus cells are derived from Susquet-Hoyer canals which function to shunt blood from the arteriolesto venules and are primarily found on hands and feet. There are two types of glomus tumors, solitaryand multiple. The solitary types tend to have paroxysmal pain which can be extreme. Multiple glomustumors can be a autosomally dominant trait with incomplete penetrance and are less likely to be

painful. Both have a predominance on the distal extremities, especially sub-ungual. Two tests arehelpful in diagnosing glomus tumors: Hildreth sign - disappearance of pain following application of a

tourniquet proximally. Love test - eliciting pain by applying pressure to a precise area with the tip of apencil.


Desmosine and isodesmosine are typical amino acids found in:

1 Collagen fibers

2 Anchoring fibril

3 Elastic fibers

4 Heparan sulfate


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5 Anchoring plaques


Desmosine and isodesmosine are typical amino acids found in:

3 Elastic fibers

Desmosine and isodesmosine are typical amino acids found in elastic fibers. They crosslink fibrillin.Anchoring fibrils are composed of collagen VII and collagen fibers and have the most typical aminoacids of proline and hydroxyproline. Heparan sulfate do not typically contain these amino acids.


The most common type of pityriasis rubra pilaris in childhood is type:

1 I

2 II

3 III

4 IV

5 V


The most common type of pityriasis rubra pilaris in childhood is type:

4 IV

Type IV, or circumscribed juvenile, accounts for 25% of total PRP cases. The most common type isType I, classical adult, which accounts for 55% of cases. Types II, III, and V account for less than10% each.


During embryogenesis, periderm cells of the fetus contain which of the following substances?

1 Ceramide

2 Glycogen

3 Free fatty acids4 Porphyrins

5 Sebum


During embryogenesis, periderm cells of the fetus contain which of the following substances?

2 Glycogen

In week 7 of embryogenesis the surface ectoderm produces two layers. The external layer is theperiderm which contains glycogen and gives rise to the stratum corneum by week 21. The other layeris the stratum germinativum.


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Which sebaceous gland is located on the buccal mucosa and vermilion border of the lips?

1 Montgomery's tubercles

2 Tysons glands3 Zeis glands

4 Meibomian glands

5 Fordyce's spots


Which sebaceous gland is located on the buccal mucosa and vermilion border of the lips?

5 Fordyce's spotsFordyce's spots are located on the buccal mucosa and vermilion border of the lips. Montgomery'stubercles are present on the areola, Tyson's glands on the labia minora and glans, meibomina andZeis glands are present on the eyelids.


Itch is most commonly transmitted by:

1 C-polymodal nociceptor class nerves

2 A-delta class nerves3 A-beta class nerves

4 Parasympathetic postganglionic fibers

5 A-beta and A-delta fibers


Itch is most commonly transmitted by:

1 C-polymodal nociceptor class nerves

Itch is transmitted primarily by C-polymodal nociceptor class nerves. These are small diameterunmyelinated nerves that carry pain, thermal, mechanical and pruritic stimuli. A-delta fibers carry

pain, thermal, mechanical and in some cases pruritic stimuli. A-beta fibers carry light touch andmotion stimuli. Parasympathetic post-ganglionic fibers do not contribute to cutaneous pruritus


Which of the following make up the major protein of the cornified cell envelope?

1 Loricrin

2 Involucrin3 Envoplakin


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4 Filaggrin

5 Laminin V


Which of the following make up the major protein of the cornified cell envelope?

1 Loricrin

Loricrin is the major protein component of the cornified cell envelope (CE). Involucrin is cross-linkedby transglutaminase in the granular layer to form an insoluble cell boundary. Envoplakin may link theCE to desmosomes and to keratin filaments. Filaggrin is thought to promote aggregation and disulfide

bonding of keratin filaments in CE. It is degraded into urocanic acid and pyrrolidone carboxylic acid.Both of which hydrate the stratum corneum and block UV radiation. Laminin V is found in the

basement membrane and is not involved in the formation of the cornified cell envelope.


In epidermolysis bullosa simplex, where on the blister does the signal localize on a salt split skin test?

1 Roof

2 Floor

3 Middle

4 Diffuse

5 No localization


In epidermolysis bullosa simplex, where on the blister does the signal localize on a salt split skin test?

1 Roof

In dystrophic EB the signal localizes to the roof of the blister. In junctional EB, the roof has BPAG2while the floor has type IV collagen.


The major protein component of the cornified envelope is:

1 Envoplakin

2 Desmoplakin

3 Plectin

4 Loricrin

5 Transglutaminase


The major protein component of the cornified envelope is:

4 Loricrin


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Loricrin is the major component of the cornified envelope (CE). The proteins of the CE aresynthesized in the spinous and granular layers. The CE is primarily a protein/lipid polymer formedwithin the differentiating layer of keratinocytes. The CE eventually exists outside of the cornified cellsafter the granular cell undergoes a programmed destruction (apoptosis). Self-destructing granular cellsare called transition cells.


All of the following are true regarding the formation of hair except:

1 The inner root sheath keratinizes by means of trichohyalin granules

2 Henles layer is outside of Huxleys layer

3 The outer root sheath is a downward extension of the epidermis

4 Huxleys layer contains melanin

5 The hair matrix becomes the hair and the inner root sheath


All of the following are true regarding the formation of hair except:

4 Huxleys layer contains melanin

The inner root sheath is composed of three layers, which are the inner root sheath cuticle, Huxleylayer, Henle layer. None of these layers contain melanin. All three layer keratinize by trichohyalinegranules and disintegrate when they reach the isthmus of the hair follicle.


Choose the correct answer regarding melanin and skin color:

1 In black and brown skin the melanosomes are smaller in diameter and length

2Facultative skin color is the amount of cutaneous melanin pigment generated according tocellular genetics

3 In white skin the melanosomes form groups within the secondary lysosomes

4 Eumelanin produces a yellow chromophore

5 The number of melanocytes increases with one exposure to UVA/visible light


Choose the correct answer regarding melanin and skin color:

3 In white skin the melanosomes form groups within the secondary lysosomes

Melanocytes of dark skin synthesize melanosomes larger than those produced in light skin. Thenumber of melanocytes in the epidermis is the same, regardless of the person's race or color: it is thenumber and size of the melanosomes or pigment granules, continuously synthesized by thesemelanocytes, that determine differences in skin color. The size of th melanosome is the principle factor

in determining how the melanosomes will be distributed within the keratinocytes. The larger themelanosomes of dark skin are individually dispersed within the cytoplasm of keratinocytes: smallermelanosomes of light skin are packaged in membrane-bound complexes within keratinocytes.


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Eumelanin is in dark oval melanosomes found in black hair


Sebaceous glands form a lipid-rich substance called sebum and are usually associated with a hairfollicle. They secrete sebum by what mechanism?

1 Vacuolar exocytosis2 Passive diffusion

3 Decapitation secretion

4 Autocrine secretion

5 Holocrine secretion


Sebaceous glands form a lipid-rich substance called sebum and are usually associated with a hairfollicle. They secrete sebum by what mechanism?

5 Holocrine secretion

Sebaceous glands form a lipid-rich substance called sebum and are usually associated with a hairfollicle. They secrete sebum by means of holocrine secretion which means that they exude lipids bydisintegration of entire sebocytes. Sebum contains numerous lipids including cholesterol, cholesterolesters, triglycerides, squalene, and wax esters. Sebaceous glands are regulated by androgens and theactivity can be regulated by retinoids.


At what estimated gestational age are all layers of the keratinized epidermis identifiable?

1 8 weeks

2 12 weeks

3 16 weeks

4 20 weeks

5 24 weeks


At what estimated gestational age are all layers of the keratinized epidermis identifiable?

5 24 weeks

At 24 weeks, all the layers of the mature epidermis can be identified, and the epidermis is keratinized.


The embryonic periderm becomes part of the1 vernix caseosa


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2 stratum corneum

3 stratum basale

4 dermis

5 hair follicle


The embryonic periderm becomes part of the

1 vernix caseosa

During the second trimester of fetal development, the periderm is sloughed from most of the skinsurface revealing the underlaying epidermis. The periderm becomes part of the protective coating,vernix caseosa, together with the shed lanugo, sebum and other amniotic fluid materials. Bolognia

p.38


The main collagen component of the basement membrane is:

1 Collagen IV

2 Collagen III

3 Collagen I

4 Tenascin-X

5 Collagen VII


The main collagen component of the basement membrane is:

1 Collagen IV

Collagen IV is the main collagen component of basement membranes. Collagen I is the main collagenof mature dermis, bone and tendon. Collagen III is found in fetal skin, blood vessels and intestines.Tenascin-X is mutated in some forms of Ehlers-Danlos syndrome and is not associated with the

basement membrane. Collagen VII makes up anchoring fibrils and amnion.


Mast cells are derived from bone marrow ____+ cells?

1 CD3

2 CD6

3 CD20

4 CD34

5 CD68Q/Q(M)-479248 Report a Problem


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Mast cells are derived from bone marrow ____+ cells?

4 CD34

CD34+ cells in the bone marrow are the precursors of mast cells. CD3 and CD20 are T and B cellmarkers respectively. CD6 is found on mononuclear phagocytic cells in the dermis, CD68 is a

macrophage marker.Q/Q(M)-479248 Report a Problem

When do melanocytes begin to synthesize melanin?

1 2nd month of gestation

2 3rd month of gestation

3 4th month of gestation




When do melanocytes begin to synthesize melanin?

2 3rd month of gestation

Melanocytes begin to synthesize melanin in the 3rd month of gestation.


Which of the following cytokines are secreted from keratinocytes?

1 IL-2

2 IL-3

3 IL-17

4 IL-22

5 IL-23


Which of the following cytokines are secreted from keratinocytes?

5 IL-23

IL-2 is a cytokine that primarily produced by T lymphocytes and acts on other T lymphocytes as agrowth factor for both survival and differentiation. IL-3 is also produced by T lymphocytes and acts asa growth factor for cells of the myeloid lineage. IL-17 is an effector cytokine that is implicated in the

pathogenesis of psoriasis and produced by Th17 cells. IL-22 is also an effector cytokine produced by T

lymphocytes that contributes to epidermal acanthosis in psoriasis. All of these cytokines are notsecreted from epidermal keratinocytes. IL-23, which promotes Th17 effector function, is secreted byepidermal keratinocytes and upregulated in psoriasis. The p40 subunit of IL-23 is the target of drug


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ustekinimab used to treat psoriasis.


Numerous neuromediators are involved in cutaneous neurobiology and many play a role in thedevelopment of inflammation in the skin. One such mediator can be induced by application ofcapsaicin to the skin. Which of the following is the correct neuromediator?

1 Noradernaline

2 Substance P

3 Neurokinin A

4 Acetylcholine

5 Pro-opiomelanocortin


Numerous neuromediators are involved in cutaneous neurobiology and many play a role in thedevelopment of inflammation in the skin. One such mediator can be induced by application ofcapsaicin to the skin. Which of the following is the correct neuromediator?

2 Substance P

Substance P is a neuromediator that binds the tachykinin receptor. It is released upon stimulation ofsensory nerve fibers. It has numerous cutaneous functions, including development of skin edema,erythema, and pruritus, upregulation of adhesion molecule expression, release of proinflammatorymediators, etc. Capsaicin causes release of substance P. This has been utilized pharmacologically inconditions such as zoster, in which consistent application of capsaicin leads to depletion of substance

P, which in turn can help to reduce/eliminate post-herpetic neuralgia. The other answer choices arealso neuromediators that are involved in cutaneous inflammation, but their release is not induced bycapsaicin.


Tissue contraction begins:

1 At 3rd day of wound healing

2 During the 2nd week of wound healing

3 After the first month of wound healing

4 After the 3rd month of wound healing

5 After the 9th month of wound healing


Tissue contraction begins:

2 During the 2nd week of wound healing

Wound healing tends to be a predictable process that begins initially with the inflammatory stage.During this stage, clot formation occurs. This is the initial step in wound healing. Platelets, neutrophilsand macrophages all migrate to the wound and secrete many mediators of wound healing.


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Epithelialization then begins hours after injury. This is followed by granulation tissue formation (fourdays after injury) and angiogenesis (first week of repair). Wound contraction ensues during the secondweek of healing.


Keratinocytes have been shown to secrete all of the following cytokines except:

1 IL-1

2 IL-6

3 IL-8

4 TNF-alpha

5 IL-2


Keratinocytes have been shown to secrete all of the following cytokines except:

5 IL-2

Keratinocytes have been shown to secrete all of the above cytokines, except IL-2, IL-4, and IFN-gamma.


Which of the following is not a specialized type of sebaceous gland?1 Moll's gland

2 Meibomian gland

3 Gland of Zeis

4 Montgomery's tubercle

5 Fordyce spot


Which of the following is not a specialized type of sebaceous gland?

1 Moll's gland

There are several types of specialized sebaceous glands that are not associated with a hair follicle.They include Montgomery's areolar tubercle, Fordyce spots of the lip, Glands of Zeis of the cutaneouseyelid, and Meibomian glands of the eyelid. Moll's gland of the eyelid are a modified apocrine gland.


Which part of the nose is not innervated by V2 branch of Cranial nerve V?

1 nasal columella


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2 nasal ala

3 nasal tip

4 nasal dorsum

5 all sensory of the nose is innervated by V2


Which part of the nose is not innervated by V2 branch of Cranial nerve V?

3 nasal tip

This is innervated by the anterior ethmoidal branch of V1. The infraorbital nerve of V2 innervates thenasal ala. The nasopalantine branch of V2 innervates the columella.


Meibomian glands are:1 Modified sebaceous glands

2 Found everywhere except on the palms and soles

3 Sebaceous lobules that feed into a lactiferous duct

4 Modified ceruminous glands

5 Modified apocrine glands


Meibomian glands are:

1 Modified sebaceous glands

Meibomian glands of the eyelids are modified sebaceous glands. Sebaceous glands are foundeverywhere on the skin except the palms and soles. Montgomery's areolar tubercles consist of severalsebaceous lobules feeding into a lactiferous duct. Ceruminous glands are apocrine glands of theexternal ear canal. Apocrine glands in the eyelids are Moll's glands.


Sebaceous glands secrete sebum via:

1 Holocrine mechanism

2 Exocrine mechanism

3 Endocrine mechanism

4 Exostosis

5 Mecrocrine mechanism


Sebaceous glands secrete sebum via:


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1 Holocrine mechanism

The sebaceous lobules have basal germinative cells and central sebocytes, which gradually becomemore distended with lipid vacuoles until they are shed into the lumen (holocrine secretion).


Asboe-Hansen Sign refers to:







Asboe-Hansen Sign refers to:


Spreading bulla phenomenon with pressure on an intact bulla is referred to as Asboe-Hansen sign,commonly seen with pemphigus vulgaris. Nikolsky sign can be seen when an intact epidermis shearsaway from the underlying dermis, leaving a moist surface (seen in pemphigus vulgaris, staphylococcusscalded skin syndrome (SSSS), and toxic epidermal necrosis). Swollen, itchy and or red after strokingthe skin is referred to Dariers sign and can be seen in systemic mastocytosis or urticaria

pigmentosa. Central depression within a lesion when squeezed is referred to as the dimpling sign andis seen in dermatofibromas. Disappearance of color or blanching when the lesion is pressed is

commonly found on vascular lesionsQ/Q(M)-482672 Report a Problem

Which sebaceous gland is located on the eyelids in association with eyelashes?

1 Montgomery's tubercles

2 Tysons glands

3 Zeis glands

4 Meibomian glands5 Fordyce's spots


Which sebaceous gland is located on the eyelids in association with eyelashes?

3 Zeis glands

Zeis glands are sebaceous glands associated with eyelashes. Montgomery's tubercles are present on theareola, Tyson's glands on the labia minora and glans, and Fordyce's spots are located on the buccal

mucosa.Q/Q(M)-482660 Report a Problem


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During a salt split skin test, if the location of the deposition if found on the roof (lamina lucida),which of the following could be a diagnosis?

1 Bullous pemphigoid

2 Anti-epiligrin cicatricial pemphigoid

3 Epidermolysis bullosa acquisita

4 Bullous eruption of lupus erythematosus

5 Bullous eruption of tinea


During a salt split skin test, if the location of the deposition if found on the roof (lamina lucida),

which of the following could be a diagnosis?

1 Bullous pemphigoidBullous pemphigoid is one of the many bullous diseases that may be found on the roof of the

blister, the others include pemphigoid gestationis, linear IgA bullous dermatosis, cicatricialpemphigoid. The other answer (except for bullous tinea, in which a salt split would not be performed)are those found on the floor of the blister (lamina densa).


Which of the following markers are specific and reliable for Merkel cells?

1 CD20

2 HMB-45

3 CD34

4 CD3

5 CK20


Which of the following markers are specific and reliable for Merkel cells?

5 CK20

Cytokeratin (CK) 20 is a reliable marker for Merkel cells. CD20 is a marker for B-cells and CD3 is aT-cell marker. HMB-45 is used in staining for immature melanosomes and is reactive in melanoma.CD34 is used to stain dermatofibrosarcoma protuberans.


Dystrophic epidermolysis bullosa results from mutations in:

1 Collagen type I

2 Collagen type II

3 Collagen type III


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4 Collagen type V

5 Collagen type VII


Dystrophic epidermolysis bullosa results from mutations in:

5 Collagen type VII

Dystrophic epidermolysis bullosa results from mutations in Type 7 collagen. Type I collagenmutations are associated with osteogenesis imperfecta. Antibodies to Type II collagen are associatedwith relapsing polychondritis. Mutations in type V collagen result in the classic form of Ehlers Danloswhile mutations in type III collagen result in the vascular form of Ehlers Danlos.


Regarding the stratum germinativum (basale):

1 Intermediate filaments in basal cells insert into only hemidesmosomes2 Keratins 1 and 10 are expressed

3 Not all basal cells have the potential to divide

4 Microfilaments assist in downward movement of cells

5 Plectins regulate adhesion and initiation of differentiation.


Regarding the stratum germinativum (basale):3 Not all basal cells have the potential to divide

Not all basal cells have the potential to divide. Stem cells give rise to transient amplifying cells whichgive rise to the epidermal keratinocytes. Intermediate filaments in basal cells insert into desmosomesand hemidesmosomes. Keratins 5/14 are predominantly expressed. Microfilaments assist in upwardmovement of cells. Integrins regulate adhesion and initiation of differentiation.


Merkel cells are mechanoreceptors found in areas of high-tactile sensitivity. Thisimmunohistochemical marker is restricted to Merkel cells in the skin and is thus a reliable marker forthese cells:

1 Keratin 7

2 Keratin 20

3 S-100

4 Factor XIIIa

5 LYVE-1



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Merkel cells are mechanoreceptors found in areas of high-tactile sensitivity. Thisimmunohistochemical marker is restricted to Merkel cells in the skin and is thus a reliable marker forthese cells:

2 Keratin 20

Keratin 20 is reliable immunohistochemical markers for Merkel cells as it is restricted to these cells inthe skin. Keratin 7 can be used as a marker for Paget's Disease. S-100 is frequently used to stain neuralcells and melanocytes. Factor XIIIa can be used to differentiate a dermatofibroma fromdermatofibroma sarcoma pertuberans (positive in DF; negative in DFSP). LYVE-1 is a marker forlymphatics.


A child presents with a 1 cm yellow-red nodule on the face. Pathology shows Touton giant cells. Whatis the most frequent site of extracutaneous involvement in this disease?

1 Eye2 Lung

3 Bone

4 CNS

5 Visceral


A child presents with a 1 cm yellow-red nodule on the face. Pathology shows Touton giant cells. Whatis the most frequent site of extracutaneous involvement in this disease?

1 Eye

The eye is the most frequent site of extracutaneous juvenile xamthogranuloma. The second mostcommon site of extracutaneous disease is the lungs. Ocular involvement is typically unilateral.


Acral melanomas are particularly concerning because they:

1 Are diagnosed at a later stage

2 Invade perineurally

3 Cannot be resected

4 Metastasize frequently even at shallow Breslow depth

5 Do not respond to ipilimumab


Acral melanomas are particularly concerning because they:

1 Are diagnosed at a later stageAcral melanoma is problematic because it is diagnosed at a later stage. It accounts for 5-10% of all


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melanomas.


What does a western blot identify?

1 Protein

2 RNA

3 DNA

4 Genes

5 Cell membranes


What does a western blot identify?

1 ProteinA northern blot identifies RNA and a southern blot identifies DNA.


Which of the following groups of adhesion proteins are found in both the hemidesomsome-anchoringfilament complexes and lamina densa?

1 Plectin

2 Heparin sulfate proteoglycan

3 Laminin 5

4 Nidogen

5 Type VII collagen


Which of the following groups of adhesion proteins are found in both the hemidesomsome-anchoringfilament complexes and lamina densa?

3 Laminin 5

Laminin 5 is found both in the hemidesomsome-anchoring filament complexes and lamina densa.Plectin is found in the hemidesomsome-anchoring filament complexes. Heparin sulfate proteoglycan isfound only in the lamina densa, collagen VII in the sublamina densa, and nidogen in the lamina densa.


Retinoids upregulate transcription of which types of collagen?

1 1 and 3

2 1 and 4

3 1 and 7


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4 3 and 7

5 4 and 7


Retinoids upregulate transcription of which types of collagen?

3 1 and 7

Retinoids upregulate the transcription of collagens one and seven thereby strengthening the dermis.


As you move upward through the epidermis toward the stratum corneum, which of the following istrue?

1 calcium increases, phospholipids decrease, sphingolipids decrease

2 calcium increases, phospholipids increase sphingolipids increase

3 calcium increases, phospholipids decrease, sphingolipids increase

4 calcium decreases, phospholipids decrease, sphingolipids decrease

5 calcium decreases, phospholipids increase sphingolipids decrease


As you move upward through the epidermis toward the stratum corneum, which of the following istrue?

3 calcium increases, phospholipids decrease, sphingolipids increaseCalcium increases, phospholipids decrease, sphingolipids increase. Calcium is needed for desmosomeformation and enzyme activation. Phospholipid content of epidermis decreases with differentiation butneutral lipids and sphingolipids (ceramide) increase with differentiation.


Nikolsky sign can be seen when:


2 Spreading bulla phenomenon with pressure on an intact bulla3 Swollen, itchy and or red after stroking the skin




Nikolsky sign can be seen when:

1 When an intact epidermis shears away from the underlying dermis, leaving a moist surfaceNikolsky sign can be seen when an intact epidermis shears away from the underlying dermis, leaving amoist surface (seen in pemphigus vulgaris, staphylococcus scalded skin syndrome (SSSS), and toxic


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epidermal necrosis). Spreading bulla phenomenon with pressure on an intact bulla is referred to asAsboe-Hansen sign, commonly seen with pemphigus vulgaris. Swollen, itchy and or red after strokingthe skin is referred to Dariers sign and can be seen in systemic mastocytosis or urticaria

pigmentosa. Central depression within a lesion when squeezed is referred to as the dimpling sign andis seen in dermatofibromas. Disappearance of color or blanching when the lesion is pressed iscommonly found on vascular lesions


Which of the following statements is true about eccrine glands?

1 Postganglionic sympathetic fibers with acetylcholine as the principal neurotransmitter

2 Postganglionic sympathetic fibers with norepinephrine as the principal neurotransmitter

3 Postganglionic parasympathetic fibers with acetylcholine as the principal neurotransmitter

4 Postganglionic parasympathetic fibers with norepinephrine as the principal neurotransmitter

5Postganglionic sympathetic fibers with both norepinephrine and acetylcholine as the principal

neurotransmittersQ/Q(M)-478148 Report a Problem

Which of the following statements is true about eccrine glands?

1 Postganglionic sympathetic fibers with acetylcholine as the principal neurotransmitter

Eccrine glands are innervated by postganglionic sympathetic fibers with acetylcholine as the principalneurotransmitter. This explains why medications associated with anticholinergic side effects may beassociated with hypohidrosis.


Keratinocytes are derived from which of the following:

1 Endoderm

2 Mesoderm

3 Ectoderm

4 Neural Crest

5 Bone marrow precursors


Keratinocytes are derived from which of the following:

3 Ectoderm

As implied by the root 'ecto', a prefix meaning "outer", the keratinocytes of the epidermis are derivedfrom the ectoderm. The other layers do contribute cell populations that are present in the skin.


What is the most abundant collagen found on fetal skin?


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1 Type I Collagen

2 Type II Collagen

3 Type III Collagen

4 Type IV Collagen

5 Type VII Collagen


What is the most abundant collagen found on fetal skin?

3 Type III Collagen

Type III collagen is found in the fetal skin. It is also present in the gastrointestinal tract, blood vessels,and the basement membrane. A defect in this collagen results in the Ehlers-Danlos, vascular type.


Which of the following diseases has decreased or absent lamellar granules?

1 Flegel's

2 Psoriasis

3 Lamellar ichthyosis

4 Epidermolytic hyperkeratosis

5 Pemphigus vulgaris


Which of the following diseases has decreased or absent lamellar granules?

1 Flegel's

Flegel's disease has decreased or absent lamellar granules. AKA hyperkeratosis lenticularis perstans,this is a rare, possibly AD disorder with multiple disc-like keratotic papules predominenty on the distalextremities and feet of older individuals (Bolognia, p 1714).


Which of the following dermal cells always express CD11c and CD6?

1 Mononuclear phagocytic cells

2 Fibroblasts

3 Mast cells

4 Erythrocytes

5 Glomus cells



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Which of the following dermal cells always express CD11c and CD6?

1 Mononuclear phagocytic cells

The mononuclear phagocytic cell includes monocytes, macrophages and dermal dendrocytes. Allphagocytic skin macrophages express CD11c and CD6. Fibroblasts do not produce a CD marker. Mastcells are derived from bone marrow-residing CD34+ stem cells. They do not produce CD11c or CD6.


Direct immunofluorescence staining of intercellular spaces and the basement membrane zone, incombination, is seen in:

1 Paraneoplastic pemphigus

2 Anti-epiligrin pemphigoid

3 Pemphigus vegetans

4 Pemphigus foliaceous

5 IgA pemphigus


Direct immunofluorescence staining of intercellular spaces and the basement membrane zone, incombination, is seen in:

1 Paraneoplastic pemphigus

Paraneoplastic pemphigus and drug-induced pemphigus demonstrate direct immunofluorescencestaining of the intercellular space and the BMZ, in combination. Anti-epiligrin pemphigoid

demonstrates BMZ staining (dermal staining on salt-split skin). Pemphigus vegetans, pemphigusfoliaceous, and IgA pemphigus all show intercellular space deposition without staining of the BMZ.


Where are glomus cells derived from?

1 Mesenchyme

2 Bone marrow

3 Susquet-Hoyer canal

4 Skeletal muscle

5 Dermis


Where are glomus cells derived from?

3 Susquet-Hoyer canal

Glomus cells are vascular smooth muscle cells derived from the arterial portion of the glomus body, or

the Sucquet-Hoyer canal, which is an arteriovenous shunt in the dermis that contributes to temperatureregulation. Glomus are found primarily on the palms and soles and function to allow the rapidshunting of blood from the arteioles to venules. Disease processes involving glomus cells include


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glomus tumor and glomangioma.


The antibody target in ocular cicatricial pemphigoid is also mutated in:

1 Junctional epidermolysis bullosa, Herlitz type

2 Recessive dystrophic epidermolysis bullosa

3 Junctional epidermolysis bullosa with myotonic dystrophy

4 Dominant dystrophic epidermolysis bullosa

5 Junctional epidermolysis bullosa with pyloric atresia


The antibody target in ocular cicatricial pemphigoid is also mutated in:

5 Junctional epidermolysis bullosa with pyloric atresiaJEB with pyloric atresia and ocular cicatricial pemphigoid both have mutations in Beta4integrin.Herlitz type JEB is due to laminin 5. Recessive and dominant dystrophic EB is due to COL17A1 (typeVII collagen). JEB with myotonic dystrophy is due to plectin.


Type VII collagen in found in anchoring fibrils and also in:

1 Fetal skin

2 Bone3 Amnion

4 Aorta

5 Blood vessels


Type VII collagen in found in anchoring fibrils and also in:

3 Amnion

Type VII collagen is present in anchoring fibrils and amnion. Fetal skin and blood vessels contain typeIII collagen. The aorta contains type VI collagen. Bone contains type I collagen.


1 melanocyte has contact with:

1 6 keratinocytes

2 12 keratinocytes

3 18 keratinocytes4 30 keratinocytes


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5 36 keratinocytes


1 melanocyte has contact with:

5 36 keratinocytes

One melanocyte and 36 keratinocytes make up one epidermal melanin unit. This melanocytes transferspigment to these keratinocytes.


Which of the following is true regarding BPAg1?

1 It is pathogenic in cicatricial pemphigoid

2 It is a member of the plakin family

3 It is pathogenic in pemphigoid gestationis

4 It is not pathogenic in paraneoplastic pemphigus

5 It coprecipitates with plakoglobin


Which of the following is true regarding BPAg1?

2 It is a member of the plakin family

BPAg1 is a member of the plakin family, which includes envoplakin, periplakin, desmoplakin, plectin,

and BPAg1. BPAg2 is pathogenic in cicatricial pemphigoid and pemphigoid gestationis. BPAg1 ispathogenic in paraneoplastic pemphigus. Desmoglein 3 is pathogenic in pemphigus vulgaris andcoprecipitates with plakoglobin.


Surgery, Parturition, Fever, Kwashiokor and Hypervitaminosis A are all causes of:

1 Telogen effluvium

2 Anagen effluvium

3 Alopecia areata4 Androgenetic alopecia

5 Both telogen and anagen effluvium


Surgery, Parturition, Fever, Kwashiokor and Hypervitaminosis A are all causes of:

1 Telogen effluvium

All of the listed stressors can induce telogen effluvium. Other causes include traction and some drugexposures. Usually will only involve up to 50% of scalp hairs and will resolve within 2-3 months.



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What component is the major barrier in the stratum corneum?

1 Sebum

2 Squalene

3 Collagen

4 Ceramide

5 Triglycerides


What component is the major barrier in the stratum corneum?

4 Ceramide

The major component of lamellar granules of the keratinocytes is ceramide. These play a major role in

the barrier function of the skin.Q/Q(M)-476553 Report a Problem

Regarding the stratum spinosum, which of the following is correct?

1 No keratin 1/10 is present

2 New synthesis of K5/14 occurs in this layer

3 The "spines" seen on pathology are due to desmosomal connections between keratinocytes

4 This layer contains melanocytes

5 This layer contains the cornified cell membrane


Regarding the stratum spinosum, which of the following is correct?

3 The "spines" seen on pathology are due to desmosomal connections between keratinocytes

The "spines" seen on pathology are due to desmosomal connections between keratinocytes, NOThemidesmosomes. The hemidesmosomes are present in the cells at the base of the basal layer and are

part of the connection between the epidermis and basement membrane. Keratin expression continuesin the spinous layer. Keratins 1/10 are synthesized, not keratins 5/14. Keratin 5/14, however, is still

present. Keratohyaline granules are typically seen in the granular layer.


Apocrine glands:

1 Demonstrate holocrine secretion

2 Demonstrate decapitation secretion

3 Are fully functional at birth

4 Are diffusely distributed on the body


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5 Are thermoregulatory


Apocrine glands:

2 Demonstrate decapitation secretion

Apocrine glands show decapitation secretion. Like eccrine glands, apocrine glands are composed ofthree segments, the intraepidermal duct, the intradermal duct, and the secretory portion. The duct ofthe apocrine gland usually leads to a pilosebaceous follicle above the entrance of the sebaceous duct.Apocrine glands are found in the axillae, anogenital region, external ear canal (ceruminous glands), inthe eyelids (Molls glands), and in the breast (mammary glands). Apocrine glans are functional onlyat puberty. Their initial secretion is odorless. Hidradenitis suppuritiva is a disease involving apocrineglands.


On electron microscopy, which cell demonstrates cytoplasmic projections and secretory granules?1 Langerhans cell

2 Keratinocyte

3 Mast cell

4 Melanocyte

5 Macrophage


On electron microscopy, which cell demonstrates cytoplasmic projections and secretory granules?

3 Mast cell

Electron microscopy of mast cells demonstrates large long villi at the periphery and round or ovalsecretory granules. Langerhans cells show a folded nucleus and rarely phagocytized melanosomes onelectron microscopy. Their characteristic feature is the presence of Birbeck granules whose disk shapewith one or two vesicles at either end represents a tennis raquet. Examination of melanocytes shows anabsence of tonofilaments or desmosomes with characteristic melanosomes in various stages offormation. Macrophages often contain phagocytized material within phagosomes.


Jessners solution includes:

1 Lactic acid, alcohol, glycolic acid, resorcinol

2 Lactic acid, alcohol, glycolic acid, TCA

3 Lactic acid, alcohol, salicylic acid, glycolic acid

4 Lactic acid, resorcinol, salicylic acid, glycolic acid

5 Lactic acid, alcohol, salicylic acid, resorcinol



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Jessners solution includes:

5 Lactic acid, alcohol, salicylic acid, resorcinol

Jessners is a superficial peeling agent, which may be used to treat dyschromia and textureabnormalities. TCA and glycolic acid are not ingredients in this formulation.


Which eponym describes vestigial lines of pigmentary demarcation?

1 Fuchter lines

2 Wallace's lines

3 Langer's lines

4 Lines of Blaschko

5 DermatomeQ/Q(M)-476758 Report a Problem

Which eponym describes vestigial lines of pigmentary demarcation?

1 Fuchter lines

Fuchter lines are vestigial lines in which the dorsal surface has more melanocytes than ventral surface.Wallace's lines are the well-demarcated lines around the margin of the foot and hand.


Which element is necessary for function of matrix metalloproteinases?

1 Iron

2 Nitrogen

3 Manganese

4 Magnesium

5 Zinc


Which element is necessary for function of matrix metalloproteinases?

5 Zinc

Matrix metalloproteinases are required for normal tissue architecture and normal turnover of theextracellular matric. All of them have zinc at the active site and require octahedral binding of calciumions to maintain structural integrity.


Anchoring filaments originate at the hemidesmosomes and insert into the:


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1 Desmosome

2 Sub basal dense plate

3 Lamina lucida

4 BPAG 180

5 Lamina densa


Anchoring filaments originate at the hemidesmosomes and insert into the:

5 Lamina densa

Anchoring filaments (smaller than anchoring fibrils) stretch from the plasma membrane through thesubbasal dense plaque and the lamina lucida to the lamina densa.


What percentage of the dry weight of skin in elastin?

1 2

2 4

3 6

4 8

5 10


What percentage of the dry weight of skin in elastin?

2 4

Elastin fibers make up 4% of dry weight of the skin, forming a complex meshwork extending fromlamina densa of the dermoepidermal junction through the dermis and into the hypodermis. Elastinshelp return the skin to the normal configuration after being stretched. Elastic fibers are 90% elastinwrapped by fibrillin microfibrils. Fibrillin is mutated in Marfan syndrome. The typical amino acidsfound in elastic fibers are desmosine and isodesmosine. Elastic fibers turn over slowly in the skin andare damaged by ultraviolet radiation.


Which of the following statements about glomus cells is correct?

1 Tumors of glomus cells are most commonly found on the tongue

2 Are of neural origin

3 Allow rapid shunting of blood from the arterioles to venules, bypassing capillaries

4 Tumors composed of glomus cells are asymptomatic

5 Tumors composed of glomus cells are often malignant



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Which of the following statements about glomus cells is correct?

3 Allow rapid shunting of blood from the arterioles to venules, bypassing capillaries

Tumors composed of glomus cells are usually PAINFUL, not asymptomatic. The are derived fromSuquet-Hoyer canals and allow rapid shunting of blood from the arterioles to venules. Glomus cells

are part of glomus tumors which are most often solitary, purple dermal nodules on the extremities.Most often, they are seen on the fingers and toes. They are usually painful and rarely malignant. Asopposed to a glomus tumor, glomangiomas are usually painless. They also most often occur onextremities, but can also occur on the trunk.


Human sebum is distinguished from lipids of internal organs by the presence of:

1 Cholestrol

2 Cholestrol esters

3 Squalene

4 Wax esters

5 Glycerides


Human sebum is distinguished from lipids of internal organs by the presence of:

4 Wax esters

As human sebum exits the sebaceous gland, its major constituents are squalene, cholesterol,cholesterol esters, triglycerides, and wax esters. With passage through the hair follicle, triyglyceridesin the sebum become hydrolyzed by bacterial enzymes, so that by the time the sebum reaches the skinsurface, it contains free fatty acids, mono- and diglycerides in addition to the original components.Human sebum is distinguished by the presence of wax esters and squalene. The lipids of humaninternal organs contain no wax esters and little squalene. The squalene that is produced in internalorgans is quickly converted to lanosterol and then to cholesterol, so it does not remain in its originalform. Human sebaceous glands do not convert squalene to sterols.


Which protein is the largest component of the cornified cell envelope?

1 Keratin

2 Involucrin

3 Profilaggrin

4 Loricrin

5 Ceramide


Which protein is the largest component of the cornified cell envelope?


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4 Loricrin

The cornified cell envelope is a durable, protein-lipid polymer that eventually acts as a mechanical andchemical barrier on the exterior of cornified cells. In the upper spinous layer, keratohyaline granulesrelease profilagrin and loricrin. Profilaggrin is cleaved to filaggrin and subsequently aggregates keratinfilaments. Loricrin is the major protein component of the cornified cell envelope and is bound to thecell membrane by transglutaminases (in addition to other structural proteins like involucrin, keratins,

elafin, cystatin A and desmosomal peptides). This forms the highly insoluble proteinaceouscomponent of the cornified cell envelope.


The desmosomal connections of the epidermis are dependent on which of the following ions?

1 Iron

2 Zinc

3 Selenium

4 Calcium

5 Sodium


The desmosomal connections of the epidermis are dependent on which of the following ions?

4 Calcium

The desmosomal connections in the epidermis are calcium dependent. The other options are notrequired for these connections.


Each of the following is true about the basement membrane zone except:

1 Anchoring filaments attach the basal cell membrane to the lamin lucida

2 Can be visualized on light microscopy with PAS staining

3 Lamina densa is composed of type IV collagen

4 Contains laminin 1 and laminin 5

5 Anchoring fibrils are composed of type VII collagenQ/Q(M)-477220 Report a Problem

Each of the following is true about the basement membrane zone except:

1 Anchoring filaments attach the basal cell membrane to the lamin lucida

The basement membrane zone is seen on staining with PAS stain. It appears as a homogenous bandapproximately 1 micron thick at the dermo-epidermal junction. The hemidesmosomal complex and

basement membrane zone play an integral role in maintaining cellular adhesion. Anchoring filaments

(primarily composed of laminin 5 and BPAG2) attach the basal cell membrane to the lamina densaNOT lamina lucida.



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Which of the following medications is concentrated in the eccrine glands?

1 Cyclophosphamide

2 Cytarabine

3 Ciprofloxacin

4 Cephalexin

5 All of the answers are correct


Which of the following medications is concentrated in the eccrine glands?

5 All of the answers are correct

The above listed drugs, as well as beta-lactam antibiotics, antifungals such as ketoconazole and

griseofulvin, are known to be secreted into eccrine sweat ducts. This feature may explain thedevelopment of neutrophilic eccrine hidradenitis and eccrine squamous syringometaplasia in thecontext of chemotherapy.


Which PPK is associated with a right-sided cardiomyopathy?

1 Haim-Munk

2 Papillon-Lefevre

3 Naxos4 Olmstead

5 Huriez


Which PPK is associated with a right-sided cardiomyopathy?

3 Naxos

Naxos is associated with right sided cardiomyopathy. It is an AR, non epidermolytic PPK in whichpatients have congenital wooly hair and fragile desmosomes. These patients are at risk for heart failureand death.


What is the most important cell for wound healing?

1 Fibroblasts

2 Neutrophils3 Macrophages


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4 Lymphocytes

5 Mast cells


What is the most important cell for wound healing?

3 Macrophages

Macrophages are the most important cell for wound healing. They secrete TFGs, cytokinas, IL-1,TNF, and PDGF. Neutropenic or lymphopenic patients do not have impaired wound healing, whereasmacrophage-deficient (quantity or function) patients heal poorly. Neutrophils however are the first celltype to flood the wound during phage I of inflammation (within first 6-8 hours); this movement isfacilitated by TGF-beta. Fibroblasts migrate into the wound by stage II (granulation) where they

produced glycosaminoglycans and fibronectin.


What structure delineates the anatomic region between the nail bed and the distal groove, where thenail plate detaches of the distal portion of the digit?

1 Nail matrix

2 Proximal nail fold

3 Lunula

4 Eponychium

5 Hyponychium


What structure delineates the anatomic region between the nail bed and the distal groove, where thenail plate detaches of the distal portion of the digit?

5 Hyponychium

The hyponychium is the structure that delineates the anatomic region between the nail bed and thedistal groove, where the nail plate detaches of the distal portion of the digit. The corneal layer of thehyponychium accumulates in part under the free margin of the nail plate. In most cases, the

hyponychium is covered by the distal nail plate, however, it may become visible in the case of nailbiters.


The formation of granulation tissue depends on the presence of:

1 Neutrophils

2 Fibronectin

3 Collagen type I

4 Platelets

5 Collagen type IV


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The formation of granulation tissue depends on the presence of:

2 Fibronectin

Granulation tissue forms approximately four days after injury. It is composed of new capillaries,

macrophages, fibroblasts, and blood vessels. The formation is dependent on the presence offibronectin. There tends to be an ordered sequence of matrix deposition. Fibronectin is deposited firstfollowed by collagen 3 and then collagen 1. Granulation tissue primarily contains type 3 collagen.


Acid keratins (K10-20) are expressed on which of the following chromosomes?

1 17

2 18

3 194 10

5 12


Acid keratins (K10-20) are expressed on which of the following chromosomes?

1 17

Acid keratins are expressed on chromosome 17 and basic keratins on chromosome 12. The other listedoptions do not have active keratin functions.


All mononuclear phagocytic cells in the dermis express:

1 CD3

2 CD6

3 CD34

4 CD68

5 CD20


All mononuclear phagocytic cells in the dermis express:

2 CD6

CD6 and CD11c are expressed on all mononuclear phagocytic cells in the dermis. CD3 is a T-cell

marker and CD20 is a B-cell marker. CD34 is expressed on mast cells and CD68 on macrophages.Q/Q(M)-479246 Report a Problem


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The microflora of pilosebaceous unit consist of which of the following:

1 Pityrosporum ovale

2 Staphylococcus aureus

3 Escherichia coli

4 Pseudomonas aeruginosa

5 Corynebacterium diphtheriae


The microflora of pilosebaceous unit consist of which of the following:

1 Pityrosporum ovale

All the above bacteria and fungi are found within sebaceous glands; the Malasssezia spp. and P. ovale

are found within the acroinfundibulum, S. epidermidis is found within the midinfundibulum, andPropionibacterium spp. deep within the follicle.


Homocystinuria has abnormal crosslinking of collagen because of a mutation in:

1 Cystathione synthase

2 Type I collagen N-peptidase gene

3 Lysyl hydroxylase

4 Tenascin X

5 Lysyl oxidase


Homocystinuria has abnormal crosslinking of collagen because of a mutation in:

1 Cystathione synthase

Homocystinuria is caused by a mutation in cystathione synthase. The main skin findings are a malarflush, livedo reticularis and leg ulcerations. A characteristic eye finding is the downward displacementof the lens. The other options are involved in abnormalities associated with Ehlers-Danlos syndrome.Lysyl hydroxylase is deficient in Kyphoscoliosis type of EDS. Tenascin X is involves in ~3% ofClassical type EDS cases. Dermatosparaxis type EDS has recessive mutations in the type I collagen N-

peptidase gene.


A specific marker of Merkel cells is:

1 Cytokeratin 10

2 Cytokeratin 153 Cytokeratin 20


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4 Loricrin

5 Envoplakin


A specific marker of Merkel cells is:

3 Cytokeratin 20

Cytokeratin 20 is a specific marker for the Merkel cell. Merkel cells are mechanoreceptors located atbody sites requiring high tactile sensitivity. Keratinocyte deformation results in a secretion ofchemokines by Merkel cells, which make synaptic connection with neurons.


How soon does epithelialization begin after a skin wound occurs?

1 Minutes

2 Hours

3 2 days

4 4 days

5 6 days


How soon does epithelialization begin after a skin wound occurs?

2 HoursRe-epithelialization begins hours after an injury occurs. Keratinocytes from residual epithelialstructures leapfrog each other. One to two days after injury, cells at the wound margin proliferate and

begin to migrate into the wound.


Which of the following enzymes does not require copper for functioning?

1 Lysyl oxidase

2 ATP7a3 Tyrosinase

4 Cystathione beta-synthase

5 Ferrochelatase


Which of the following enzymes does not require copper for functioning?

5 FerrochelataseAll of the listed enzymes are copper containing or dependent except ferrochelatase. Lysyl oxidase


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facilitates crosslinking of fibrillin in elastic fibers. ATP7a is deficient in Menkes Kinky HairSyndrome. Cystathione beta-synthase is defective in homocystinuria. Tyrosinase catalyzes the first 2steps, and at least 1 subsequent step, in the conversion of tyrosine to melanin. Ferrochelatase mutationleads to excess protoporphyrin production and photosensitivity.


Direct immunofluorescence is of no value in the diagnosis of:

1 Neonatal LE

2 Lichen planus

3 Mixed connective tissue disease

4 SLE

5 Erythema multiforme


Direct immunofluorescence is of no value in the diagnosis of:

1 Neonatal LE

DIF is of no value in the diagnosis of scleroderma, morphea, and neonatal LE. DIF of lichen planus ispositive in the vast majority, with granular DEJ deposition and IgM and fibrinogen staining withincytoid bodies in the superficial dermis. In MCTD DIF shows IgG deposits within epidermal cellnuclei, and rarely along the DEJ. In SLE, while serology is more reliable, DIF can show DEJdeposition in the lupus band test. DIF of erythema multiforme shows immunoglobulin within

superficial vessel walls, DEJ, and cytoid bodies.Q/Q(M)-480546 Report a Problem

Which of the following stains would you expect to be positive in a normal eccrine unit?

1 S-100

2 Prussian blue

3 Giemsa

4 Verhoeff von Gieson

5 Steiner


Which of the following stains would you expect to be positive in a normal eccrine unit?

1 S-100

Eccrine glands stain S-100 and CEA positive. The remaining stains would not be expected to stainnormal eccrine sweat glands. Prussian blue (Perls) is an iron stain which stains iron or hemosiderin

bright blue. Giemsa stains mast cell granules purple (heparin in the granules) and can also be useful in

staining in Leishmaniasis. Verhoeff von Gieson is a stain for elastic tissue that stains blue-black.Steiner stain is a silver stin for spirochetes similar to a Warthin Starry or Dieterle stain.


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Which is a major criterion for the diagnosis of neurofibromatosis type 1?

1 One plexiform neurofibroma

2 Scoliosis

3 Pheochromocytoma

4 Hypertension

5 Two caf au lait macules


Which is a major criterion for the diagnosis of neurofibromatosis type 1?

1 One plexiform neurofibroma

The major diagnostic criteria are: 6 or more caf au lait macules >5mm in prepubertal individuals and>15mm in post pubertal individuals, 2 or more neurofibromas of any type or one plexiformneurofibroma, axillary or inguinal freckling, 2 or more lisch nodules, sphenoid wing dysplasia orthinning of long bone cortex with or without pseudoarthosis, first degree relative with NF1.


Which of the following polypeptides is found in the lamina lucida?

1 plakoglobin

2 desmoplakin3 keratocalmin

4 demoyokin

5 laminin 5


Which of the following polypeptides is found in the lamina lucida?

5 laminin 5

Laminin-5 is a basement membrane extracellular matrix protein that mediates attachment substrate forboth adhesion and migration in a wide variety of cell types, including epithelial cells, fibroblasts,neurons and leukocytes and is a preferred adhesion substrate for epithelial cells (Koshikawa et al.,2001). The remaining listed items are part of the desmosomal plaque in the epidermis.


Sneddon Wilkinson disease is caused by a defect in what antigen?

1 Desmocollin 1

2 Desmoglein 13 Desmogelin 3


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4 BPAg1

5 BPAg2


Sneddon Wilkinson disease is caused by a defect in what antigen?

1 Desmocollin 1

Sneddon- Wilkinson disease, also known as sub-corneal pustular dermatosis is due to a defect indesmocollin 1. Desmoglein 1 defect is seen in pemphigus foliaceous and staph scalded skin syndrome.Desmoglein 3 defect is seen in pemphigus vulgaris and intraepidermal neutrophilic IgA dermatosis.BPAg1 is seen in paraneoplastic pemphigus and bullous pemphigoid. BPAg2 is seen in bullous

pemphigoid, cicatricial mucous membrane pemphigoid and linear IgA disease.


Type 1 collagen is the most prevalent collagen in skin, accounting for 80% or more of the total

collagen in the adult dermis. The next most predominant collagen in adult human dermis is:

1 Type II collagen

2 Type III collagen

3 Type IV collagen

4 Type VII collagen

5 Type XVII collagen


Type 1 collagen is the most prevalent collagen in skin, accounting for 80% or more of the totalcollagen in the adult dermis. The next most predominant collagen in adult human dermis is:

2 Type III collagen

Type 1 collagen is the most prevalent collagen in skin, accounting for 80% or more of the totalcollagen in the adult dermis. Type III collagen is the next most predominant collagen in humandermis, accounting for approximately 10%. Type IV collagen is found in basement membranes. TypeVII collagen is found in human dermis as anchoring fibrils. Type XVII collagen, also known asBPAG2, is an important transmembrane protein in the basement membrane zone.


Sebaceous glands:

1 Respond to chemical stimuli such as hormones

2 Respond to cholinergic neural activity, exclusively

3 Respond to adrenergic neural activity, exclusively

4 Respond to both adrenergic and cholinergic stimuli

5 Respond to the local release of cytokines from inflammatory cellsQ/Q(M)-474175 Report a Problem


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Sebaceous glands:

1 Respond to chemical stimuli such as hormones

Sebaceous glands are androgen-responsive holocrine glands that enlarge at puberty. Meibomian glandsof the eyelids are modified sebaceous glands. Sebaceous glands are found everywhere on the skin

except the palms and soles. Fordyces condition involves free sebaceous glands on the vermillionborder of the lips and on the buccal mucosa. Eccrine glands are thermoregulatory structures thatrespond to cholinergic stimulation.


Which epidermal layer do pilar cysts generally not have a:

1 Stratum corneum

2 Stratum granulosum

3 Stratum spinosum4 Stratum basale

5 Stratum lucidum


Which epidermal layer do pilar cysts generally not have a:

2 Stratum granulosum

Pilar cysts do not have a granular layer, they do have all the other layers.


At any one time, the approximate proportion of hair follicles in anagen is:

1 40%

2 60%

3 85%

4 95%

5 15%Q/Q(M)-474172 Report a Problem

At any one time, the approximate proportion of hair follicles in anagen is:

3 85%

Most hair follicles are in anagen, and thus most hair follicles involve growing hair. The longer a hairfollicle is anagen, the longer the hair can grow in length. Hairs of the scalp grow approximately 0.4mm per day, and thus the date of your next hair cut can be accurately calculated.



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Which of the following statements about elastic fibers is true?

1 Elastic fibers form 35% of the dry weight of the skin

2 Elastic fibers are 90% elastin wrapped in fibrillin

3 Collagen 1 is mutated in Marfan syndrome

4 Oxytalan fibers run parallel within the superficial papillary dermis

5 Elaunin fibers run perpendicular in thin bands within the reticular dermis


Which of the following statements about elastic fibers is true?

2 Elastic fibers are 90% elastin wrapped in fibrillin

Elastic fibers are responsible for much of the elasticity of the dermis. They are essentially 90% elastinwrapped in fibrillin. They form 4% of the dry weight of the skin. Fibrillin 1 is mutated in Marfansyndrome. Oxytalan fibers run PERPENDICULAR from the DEJ within the superficial papillary

dermis. Elaunin fibers run parallell in thin bands within the reticular dermis.Q/Q(M)-478199 Report a Problem

Pick the correctly paired keratin with its structure:

1 K1/K10 - basal cells

2 K3/K12 - esophagus

3 K4/K13 - cornea

4 K5/K14 - suprabasal cells

5 K16/K6 - palms and soles


Pick the correctly paired keratin with its structure:

5 K16/K6 - palms and soles

Keratin 1 and 10 are found in the stratum spinosum. K5 and K14 are found in the basal layer. K3 andK12 are found in the suprabasilar cells of the cornea. K4 and K13 are found in the non-cornifying cellsof stratified mucosa. K16 and K6 are found in the palms and soles.


Necobiosis is characteristic of which two entities below?

1 Sarcoid and granuloma annulare

2 Sarcoid and necrobiosis lipoidica

3 Sarcoid and annular elastolytic giant cell granuloma

4 Granuloma annulare and necrobiosis lipoidica

5 Granuloma annulare and cutaneous Crohns disease



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Necobiosis is characteristic of which two entities below?

4 Granuloma annulare and necrobiosis lipoidica

Necrobiosis is seen in GA and NLD as well as rheumatoid nodules, interstitial granulomatousdermatitis and palisading neutrophilic and granulomatous dermatitis. Mucin is also present in GA.

NLD shows giant cells, extracellular lipid, and vascular changes.Q/Q(M)-482778 Report a Problem

Which of the following keratins would most likely be expressed in the nail bed?

1 K6a/16

2 K6b/17

3 K1/9

4 K2e/10

5 K4/13


Which of the following keratins would most likely be expressed in the nail bed?

2 K6b/17

Keratins 6b & 17 are expressed in the nail bed. K6a/16 is expressed in the outer root sheath and inhyperproliferative keratinocytes, 1/9 in palmoplantar suprabasalar keratinocytes, 2e/10 in the upperspinous and granular cell layers, and 4/13 are expressed in mucosal epithelium.


Sebaceous glands secrete sebum through which of the following secretory mechanisms?

1 Holocrine

2 Merocrine

3 Apocrine

4 Holocrine and Merocrine

5 Holocrine and ApocrineQ/Q(M)-478152 Report a Problem

Sebaceous glands secrete sebum through which of the following secretory mechanisms?

1 Holocrine

Sebaceous glands exhibit holocrine secretion, whereby the sebocytes disintegrate in transit to the glandcenter, releasing their sebum contents. Merocrine secretion refers to the formation of intracellularsecretory vesicles that translocate to the apical cell surface for secretion. Apocrine secretion refers to

the process whereby secretory contents are packaged using the apical cell membrane, and 'pinched off'to achieve secretion.



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Which hair condition is associated with abnormal regulation of the peroxisome proliferator-activatedreceptor- (PPAR):

1 Alopecia areata

2 lichen planopilaris

3 telogen effluvium

4 seborrheic dermatitis

5 androgenic alopecia


Which hair condition is associated with abnormal regulation of the peroxisome proliferator-activatedreceptor- (PPAR):

2 lichen planopilarisLichen planopilaris is a chronic, scarring condition that results in permanent loss of hair anddestruction of the hair follicles. Defect in lipid metabolism and peroxisome biogenesis may contributeto LPP pathogenesis. Medications that act as PPAR agonists, such as pioglitazone, may have a role incontrolling the progression of this disease. (Karnik P, et al. (2009) Hair follicle stem cell-specificPPAR deletion causes scarring alopecia. J Invest Dermatol 129:124357)


Defects in what kind of structural protein lead to pyloric atresia associated with junctional

epidermolysis bullosa:1 Collagen

2 Elastin

3 Loricrin

4 Integrin

5 Plectin


Defects in what kind of structural protein lead to pyloric atresia associated with junctionalepidermolysis bullosa:

4 Integrin

Junctional epidermolysis bullosa with pyloric atresia involves a defect in the b4 subunit of the a6b4integrin. The expression of this protein is limited to the basal layer of the epidermis. This integrin is atransmembrane protein that coordinates a link between the intermediate filaments (keratins) and theextracellular matrix of the basement membrane. The b4 domain mediates an interaction with both

plectin and BP180; its absence prevents hemidesmosomal assembly.



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Which of the following options is characteristic of integrins?

1Defects in the alpha-6 domain of integrin result in epidermolysis bullosa simplex with musculardystrophy

2 Alpha-6-Beta-4 integrin is found at sites where desmogleins attach

3 Expression is seen in all layers of the epidermis

4 The extracellular alpha6 domain binds collagen 75

These proteins coordinate linkage between intermediate filaments and extracellular matrix ofthe basement membrane


Which of the following options is characteristic of integrins?

5These proteins coordinate linkage between intermediate filaments and extracellular matrix ofthe basement membrane

Defects in the BETA-4 (not alpha-6) domain of integrin result in junctional epidermolysis bullosa with

pyloric atresia. Its expression is seen in the basal cell layer and binds to laminins.Q/Q(M)-478170 Report a Problem

What is the location of the unbound corticosteroid receptor?

1 Cytoplasm

2 Nucleus

3 Mitochondria

4 Plasma membrane

5 golgi apparatus


What is the location of the unbound corticosteroid receptor?

1 Cytoplasm

Both androgen and corticosteroid receptors localize to the cytoplasm. Estrogen receptors are found inthe nucleus. Progesterone receptors are distributed in both the nucleus and the cytoplasm.


The main permeability barrier in the lamina densa is:

1 heparan sulfate proteoglycan

2 collagen IV

3 laminin 5

4 nidogen

5 alpha-6-beta-4 integrinQ/Q(M)-479178 Report a Problem


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The main permeability barrier in the lamina densa is:

1 heparan sulfate proteoglycan

All of the listed proteins are present in the lamina densa except alpha-6-beta-4 integrin, whichconnects the hemidesmosome to laminin 5 in the lamina lucida. The heparin sulfate proteoglycans

(perlecan) are negatively charged, thus serve as a permeability barrier. The other listed proteins do notserve this function in the lamina densa. Collagen IV is the main basic basement membrane scaffold.Defects in Collagen IV have been linked to Alports and Goodpastures syndrome. Nidogen has adumbbellshape and binds both laminins and collagen IV in the lamina densa.


Spontaneous mutations causing tuberous sclerosis are more likely to occur in which gene?

1 TSC2

2 TSC1

3 TSC 3

4 TSC 4

5 TSC 5


Spontaneous mutations causing tuberous sclerosis are more likely to occur in which gene?

1 TSC2

Spontaneous mutations are four times more likely to occur in TSC2. In familial TS half mutations arein TSC1 and half in TSC2.


Apocrine glands are found in all of the following areas of the body except:

1 Axillae

2 Breasts

3 Eyelid

4 Palms

5 Perineum


Apocrine glands are found in all of the following areas of the body except:

4 Palms

Apocrine glands operate by decapitation secretion and are activated by epinephrine and

norepinephrine. They are located in a few distinct areas of the body, which include axillae, anogenitalregion, Molls glands of the eyelids, mammary glands of the breast and the ceruminous glands of theexternal auditory canal.


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Elastic fibers contain the specific amino acids:

1 Lysine and proline

2 Leucine and isoleucine

3 Alanine and phenylalanine

4 Desmosine and isodesmosine

5 Glycine and proline


Elastic fibers contain the specific amino acids:

4 Desmosine and isodesmosine

Desmosine and isodesmosine are the typical amino acids of elastic fibers. Elastic fibers are comprisedof elastin that is wrapped by fibrillin microfibrils. Elastic fibers form a complex meshwork extendingfrom the lamina densa of the dermo-epidermo junction through the dermis. Elastic fibers return theskin to a normal shape after being stretched.


Which component of hair is positive for citrulline?

1 Outer root sheath

2 Inner root sheath3 Cortex

4 Glassy vitreous layer

5 Medulla


Which component of hair is positive for citrulline?

2 Inner root sheath

The inner root sheath stains red because it contains citrulline. The cortex and medulla along with thecuticle make up the hair shaft. The outer root sheath is the most peripheral cellular structure. Theglassy vitreous layer is the basement zone equivalent of hair and is the outermost layer.


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Basic Science and Sructure of Skin MCQs

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