Differential Diagnosis

• Case 1: Non-scaly papulesA 27 yo call center agent complains of erythematous papules & nodules on the face especilally on the forehead, chin, cheeks & chin. She claims that she's had this problem since she was high school. Her elder brother had the same lesions.

Patient 27/F Miliaria Rubra ("heat rash", "prickly heat")

retention of sweat as a result of occlusion of eccrine sweat ducts that produces an eruption

Age of onset since high school persons of any age, but most common in infants

Epidemiology hot, humid, tropical climatesEtiology high heat and humidity

Typical lesion erythematous papules & nodules discrete, extremely pruritic, erythematous papulovesicles

Course days to weeks of exposure to hot environmentSites frequently

affectedon the face ( forehead,

cheeks & chin)antecubital, popliteal fossae, trunk, inflammatory areas, abdomen,

inguinal regions; face and volar areas are sparedManagement prickling, burning or tingling-like pain

Patient 27/F Miliaria Rubra ("heat rash", "prickly heat")

retention of sweat as a result of occlusion of eccrine sweat ducts that produces an eruption

Age of onset since high school persons of any age, but most common in infants

Epidemiology hot, humid, tropical climatesEtiology high heat and humidity

Typical lesion erythematous papules & nodules discrete, extremely pruritic, erythematous papulovesicles

Course days to weeks of exposure to hot environmentSites frequently

affectedon the face ( forehead,

cheeks & chin)antecubital, popliteal fossae, trunk, inflammatory areas, abdomen,

inguinal regions; face and volar areas are sparedOther clinical

features prickling, burning or tingling-like pain

Management controlling heat and humidity; removal of occlusive clothing, lots of fluids and cooler environment

Patient 27/F Scabies (“the Itch”)

Sarcopetes scabiei (itch mite)Age of onset since high school persons of any age

Epidemiology egalitarian; crowded and unhygienic living conditions Etiology skin-to-skin contact with an infected person, contaminated linens

Typical lesion erythematous papules & nodules pruritic papular lesions, excoriations and burrows

Course previously exposed: 2-4 daysno exposure: 4-6 weeks

Sites frequently affected

on the face ( forehead, cheeks & chin)

finger webs, wrists, axillae, areolae, umbilicus, lower abdomen, genitals and buttocks; scalp and face are spared

Other clinical features

intense pruritus (intense at night)women: itching of the nipples

men: itchy papules on the scrotum and penisManagement Permethrin 5% cream (Elimite)

Patient 27/FInsect Bites

beetles, mitesAge of onset since high school persons of any age

Epidemiology mostly children and those who work outdoorsEtiology insect bites

Typical lesion erythematous papules & nodules

Grain Itch: urticarial papule, intense pruritusBeetles: papulovesicular and urticarial dermatitis

Course immediateSites frequently

affectedon the face ( forehead,

cheeks & chin)Grain Itch: trunk

Beetles: chest, neck and forearmsOther clinical

features Pain, slight burning and tingling of the skin

Management Antihistamines; calamine lotion

Patient 27/F Acne Vulgaris

Chronic inflammatory disease of the pilosebaceous folliclesAge of onset since high school begins at puberty (15-18y/o)

“disease of the adolescents”Epidemiology Adolescent: M > F

Not limited to adolescent12% of women and 5% of men at age 25 years have acne

By age 45 years, 5% of both men and women still have acneEtiology Hyperproliferation of keratinocytes

Propionibacterium acnesTypical lesion erythematous papules

& nodulescharacterized by comedone, papules, nodules, pustules, and

even scarsCourse

Sites frequently affected

on the face ( forehead, cheeks & chin)

affects face, neck, upper trunk and upper arms

Management topical treatment - Topical Retinoids, Benzoyl Peroxide, Topical Antibacterials, Sulfur, Sodium Sulfacetamide, Resorcin,

and Salicylic Acid, Azeleic AcidOral antibiotics – tetracycline, erythromycin, clindamycin

Other antibiotics – Sulfonamides, Trimethoprim-sulfamethoxazole, Trimethoprim, Dapsone

Patient 27/F Furuncles / Carbuncles

Furuncles are skin abscesses caused by staphylococcal infection, which involve a hair follicle and surrounding tissue

Carbuncles are clusters of furuncles connected subcutaneously, causing deeper suppuration and scarring;

smaller and more superficial than subcutaneous abscessesAge of onset since high school Young people

Epidemiology M > FEtiology Staphylococcus infection

Typical lesion erythematous papules & nodules

nodule, pustule, or an acute, round, tender, circumbscibed perifollicular staphylococcal abscess

Carbuncles = two or more confluent furuncles with separate heads

Course most undergo central necrosis and rupture through the skindischarge purulent, necrotic debris;

often continue for a prolonged period by autoinoculationSites frequently

affectedon the face ( forehead,

cheeks & chin)hair-bearing regions: beard area, nape, axilla, buttocks, but may

occur anywhereOther clinical

featurescarbuncles may be accompanied by fever and prostration

Management Warm compress, Penicillinase-resistant penicillins, 1st gen cephalosporin, Bactroban oinment, Incision and drainage

Furuncle

Carbuncle

Patient 27/F Pediculosis capitis Pediculosis corporis Pediculosis pubis

infestation of lice -- blood-feeding ectoparasitic insects of the order Phthiraptera

Age of onset since high school school-age children (3-10 years old)

Epidemiology F > MBlack race - rare

M > FAdults > children

Etiology Pediculosis humanis var. capitis

(head louse)

Pediculosis humanae var.

corporis ( body louse)

Phthirus pubis(crab louse)

Typical lesion erythematous papules & nodules

Erythematous macules, or

urticarial wheals;Excoriated papules,

parallel linear stretch marks;

Transmission Head-to-head contact (most

efficient);Through inanimate

objects will play (shared combs and

brushes )

shared towels may play a role

Sexually transmitted

Patient 27/F Pediculosis capitis Pediculosis corporis Pediculosis pubis

Sites frequently affected

on the face ( forehead, cheeks & chin)

scalp upper back;no involvement of

hands and feet

usually seen in the hairy areas of the

vulvaOther clinical

featuresintense pruritus of the scalp; affected hair becomes dry

and lusterless

generalized itching; pigmented

thickening of skin from continued

scratching

characterized by constant itching

Management PermethrinPyrethrins,

combined with piperonyl butoxide

Proper hygiene;Destruction of lice:

Laundering the beddings and

clothing, Disinfection

Topical application of 1% Permethrin cream rinse (Nix)

which is applied to affected area and wash off after 10

minutes;1% Lindane

shampoo (Kwell), applied for 4

minutes to affected area and

subsequently washed off

Pediculosis Capitis

Pediculosis corporis

Pediculosis pubis