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Blotches:Light rashes

Medical Student Core Curriculum in Dermatology

Last updated April 18, 2011

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Module Instructions

The following module contains a number of blue, underlined terms which are hyperlinked to the dermatology glossary, an illustrated interactive guide to clinical dermatology and dermatopathology.

We encourage the learner to read all the hyperlinked information.

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Goals and Objectives

The purpose of this module is to help medical students develop a clinical approach to the evaluation and initial management of patients presenting with light rashes.

After completing this module, the medical student will be able to:• Identify and describe the morphology of common light rashes• Describe the use of Wood’s lamp and KOH exam to evaluate

light spots• Recommend an initial treatment plan for selected light rashes• Determine when to refer to a patient with a light rash to a

dermatologist

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Case OneHeather Doyle

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Case One: History

HPI: Heather Doyle is a 10-year-old girl who presents with several lightly colored spots on her knees and hands over the past 8 months. They do not itch. Her mother reports they have not improved with over-the-counter hydrocortisone cream.

PMH: no chronic illnesses or prior hospitalizations Allergies: penicillin (rash) Medications: none Family history: grandmother with diabetes Social history: lives at home with parents; attends elementary

school; takes karate lessons ROS: negative

Case One: Skin Exam

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Case One, Question 1

Heather has some light colored, non-scaly, flat spots on her knees. Which of the following will likely aid in the diagnosis?

a. Dermatoscopeb. Potassium hydroxide (KOH) examc. Swab for bacterial cultured. Wood’s light

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Case One, Question 1

Answer: d Heather has some light colored, non-scaly,

flat spots on her knees. Which of the following will likely aid in the diagnosis?

a. Dermatoscopeb. Potassium hydroxide (KOH) examc. Swab for bacterial cultured. Wood’s light

Case One: Wood’s light exam

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Case One, Question 2

How would you describe Heather’s exam?a. well-circumscribed hypopigmented macules

and patchesb. well-circumscribed depigmented macules and

patchesc. poorly circumscribed hypopigmented macules

and patchesd. poorly circumscribed hypopigmented papules

and plaques

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Case One, Question 2

Answer: b How would you describe Heather’s exam?

a. well-circumscribed hypopigmented macules and patches

b. well-circumscribed depigmented macules and patches

c. poorly circumscribed hypopigmented macules and patches

d. poorly circumscribed hypopigmented papules and plaques

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Vitiligo

Lesions of vitiligo are well-circumscribed depigmented macules and patches.

The Wood’s light exam distinguishes hypopigmented and depigmented lesions.

Very few rashes other than vitiligo are completely depigmented.

More Examples of Vitiligo

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Demonstration of bright white (depigmented) area with Wood’s light illumination

Vitiligo: The Basics

Vitiligo is caused by an autoimmune attack on melanocytes, the cells that produce skin pigment

It favors areas of trauma (knees, elbows, fingers, mouth, eyes, genitalia)

There is an association with other autoimmune disorders• Heather’s vitiligo may be autoimmune, given her

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Vitiligo: The Basics

Treatment options include• Potent topical steroids or tacrolimus

ointment• Phototherapy (Narrow band UVB, UVA)• Cosmetic cover-ups

Refer vitiligo patients to dermatology for initial evaluation

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Is this hypopigmented or depigmented? Use the Wood’s light.

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Wood’s light exam

Lighter areas without complete loss of pigment are “hypopigmented”

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Steroid hypopigmentation

Skin lightening can result from potent topical or intralesional corticosteroids

The risk is higher in darker skin types. Counsel patients and parents on this risk.

Avoid this side effect by using appropriate strength topical steroids• Use high-potency steroids for short durations

• Then back off to mid-potency or low-potency steroids for maintenance

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Case TwoTony Maddox

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Case Two: History

HPI: Tony Maddox is a 32-year-old man who presents with “blotches” on his upper back and chest for several years. They are more noticeable in the summertime.

PMH: back pain, hyperlipidemia, birthmark (Nevus of Ito) on his left chest

Allergies: none Medications: NSAID as needed Family history: none Social history: aircraft mechanic ROS: negative

Case Two: Skin Exam

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Case Two, Question 1

Mr. Maddox’s skin exam shows hypopigmented, slightly scaly macules on his upper chest. Which is the best test to confirm the diagnosis?

a. Bacterial cultureb. Direct fluorescent antibody (DFA) testc. Potassium hydroxide (KOH) examd. Wood’s light

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Case Two, Question 1

Answer: c Mr. Maddox’s chest shows hypopigmented,

slightly scaly macules on his upper chest. Which is the best test to confirm the diagnosis?

a. Bacterial cultureb. Direct fluorescent antibody (DFA) testc. Potassium hydroxide (KOH) examd. Wood’s light

Case Two: KOH exam

The KOH exam shows short hyphae and small round spores. This is diagnostic of tinea (pityriasis) versicolor.

Spores (yeast forms)

ShortHyphae

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Diagnosis: Tinea versicolor

Based on his skin findings and KOH exam, Mr. Maddox has tinea versicolor

It’s called “versicolor” because it can be light, dark, or pink to tan

Let’s look at some examples of the various colors of tinea versicolor

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Tinea versicolor: lighter

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Tinea versicolor: darker

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Tinea versicolor: pink or tan

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Case Two, Question 2

What is the best treatment for Mr. Maddox?a. Ketoconazole shampoob. Narrow band UVB phototherapyc. Oral griseofulvind. Tacrolimus creame. Triamcinolone cream

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Case Two, Question 2

Answer: a What is the best treatment for Mr. Maddox?

a. Ketoconazole shampoob. Narrow band UVB phototherapy (may worsen

appearance by increasing contrast)c. Oral griseofulvin (does not work for Malassezia

species)d. Tacrolimus cream (does not fight yeast)e. Triamcinolone cream (does not fight yeast)

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Case Two, Question 3

What is true about the treatment of tinea versicolor?a. Normal pigmentation should return within a

week of treatmentb. Oral azoles should be used in most casesc. When using shampoos as body wash, leave

on for ten minutes before rinsing

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Case Two, Question 3

Answer: c What is true about the treatment of tinea

versicolor?a. Normal pigmentation should return within a week of

treatment (usually takes weeks to months to return to normal)

b. Oral azoles should be used in most cases (mild cases can be treated with topicals)

c. When using shampoos as body wash, leave on for ten minutes before rinsing

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Case ThreeShaun Lee

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Case Three: History HPI: Shaun Lee is a 20-year-old male seen in the hospital with

a worsening light colored scaling rash on his face. It has been getting worse since he stopped taking HAART for HIV. He also has painful erosions and ulcers in his mouth for 2 months and was admitted for pneumonia.

PMH: HIV, extensive molluscum contagiosum, pneumonia Allergies: penicillin (rash) Medications: levofloxacin Family history: noncontributory Social history: lives at home with parents; father does not

believe he should take HIV medications ROS: fatigue, dyspnea, fevers

Case Three: Skin Exam

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Case Three, Question 1

Shaun’s exam shows hypopigmented scaling patches on his central face, eyebrows, and hairline. KOH is negative. What is the most likely diagnosis?

a. Pityriasis albab. Seborrheic dermatitisc. Steroid hypopigmentationd. Tinea versicolor

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Answer: b Shaun’s exam shows hypopigmented scaling

patches on his central face, eyebrows, and hairline. KOH is negative. What is the most likely diagnosis?a. Pityriasis alba (no history of atopy)b. Seborrheic dermatitisc. Steroid hypopigmentation (not using steroids)d. Tinea versicolor (wrong location)

Case Three, Question 1

Seborrheic dermatitis Seborrheic dermatitis is a very common inflammatory

reaction to the Malassezia (Pityrosporum ovale) yeast that thrives on seborrheic (oil-producing) skin

It presents as erythematous scaling macules on the scalp, hairline, eyebrows, eyelids, central face and nasolabial folds, external auditory canals, or central chest

It can be hypopigmented, especially in darker skin types

Seborrheic dermatitis is often worse in HIV-positive individuals

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Seborrheic dermatitis

Often hypopigmented in darker skin types

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Seborrheic dermatitis

Favors central chest. May be hypopigmented or erythematous.

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Case Three, Question 2

What is the best treatment for Shaun?a. Caspofungin IV infusionb. Clobetasol proprionate cream (high potency

steroid)c. Desonide cream (low potency steroid)d. Imiquimod creame. Narrow band UVB phototherapy

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Case Three, Question 2

Answer: c What is the best treatment for Shaun?

a. Caspofungin IV infusion (this is a systemic antifungal for severe infections)

b. Clobetasol proprionate cream (would work, but too potent for use on the face)

c. Desonide cream (low potency steroid)d. Imiquimod cream (irritating; for warts, actinic keratoses)e. Narrow band UVB phototherapy (doesn’t work)

Seborrheic dermatitis treatment Antidandruff shampoo

• Ketoconazole (Nizoral), selenium sulfide, zinc pyrithione (Head & Shoulders) shampoos

• Lather, leave on 10 minutes, rinse• 3-5 times weekly until under control

Low-potency topical steroid (e.g. desonide) for flares

• Use BID for 1-2 weeks for flares Can also use topical ketoconazole or ciclopirox, or

topical pimecrolimus43

Seborrheic dermatitis (scalp) Severe scalp seborrheic dermatitis may need

topical steroids; adjust to severity, patient ethnicity Triamcinolone spray BID for flares Fluocinolone in peanut oil (DermaSmooth™)

• Wet scalp; leave on 8 hours then wash out• If wash hair daily, apply at night with shower cap• If not, use a little oil each morning

Clobetasol foam daily after shower if severe• Towel dry and apply directly to damp scalp

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A note on postinflammatory hypopigmentation

Some patients heal with light spots from any rash

Stigma may be caused by fear of infectious diseases

Social impact can be more severe than original rash

Pigmentation may return slowly

It is important to treat rashes aggressively to avoid this if possible

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Case FourDamien Gonsalves

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Case Four: History

HPI: Damien Gonsalves is a 8-year-old boy who presents with light spots on his face.

PMH: had “eczema” as infant and young child Allergies: none Medications: none Family history: brother with asthma, mother has

seasonal allergic rhinitis Social history: lives at home with parents; student in

second grade ROS: negative

Case Four: Skin Exam

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Case Four: Question

Damien has hypopigmented patches on his cheeks bilaterally. The most likely diagnosis is:

a. Pityriasis alba

b. Seborrheic dermatitis

c. Tinea versicolor

d. Vitiligo

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Case Four: Question

Answer: a Damien has hypopigmented patches on his

cheeks bilaterally. The most likely diagnosis is:a. Pityriasis alba (atopic history supports this)

b. Seborrheic dermatitis (usually more central)

c. Tinea versicolor (rarely occurs on the face)

d. Vitiligo (would be depigmented, not hypopigmented)

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Pityriasis alba

Pityriasis alba is a mild form of atopic dermatitis of the face in children

As in all atopic dermatitis, the first goal is moisturization

Use of sunscreens minimizes tanning, thereby limiting the contrast between involved and normal skin

If moisturization and sunscreen do not improve the hypopigmentation, consider low strength topical steroid

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Common light rashes

Vitiligo Tinea versicolor Seborrheic dermatitis Pityriasis alba

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Comparing common light rashes

Face Trunk Arms, Legs Notes

Seborrheic dermatitis X X Central face

Greasy scale

Tinea versicolor X + KOH positive

Vitiligo X + XDepigmented (“bone

white”) on Woods light exam

Pityriasis alba X History of atopy53

Take Home Points: Light Rashes Vitiligo is totally depigmented (“bone white”) on Wood’s light

examination Hypopigmented macules on the upper back and chest should

be scraped for KOH exam to rule out tinea versicolor Hypopigmented patches on the central face with greasy scale

are usually seborrheic dermatitis Hypopigmented patches on the face of atopic children are

usually pityriasis alba; reassure parents and encourage use of sunscreen and moisturizers

Potent corticosteroids can cause hypopigmentation, so be aware of that when prescribing or injecting, and warn patients of this possible side effect when appropriate

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Acknowledgements

This module was developed by the American Academy of Dermatology Medical Student Core Curriculum Workgroup from 2008-2012.

Primary author: Patrick McCleskey, MD, FAAD. Peer reviewers: Timothy G. Berger, MD, FAAD;

Peter A. Lio, MD, FAAD; Jennifer Swearingen, MD; Sarah D. Cipriano, MD, MPH.

Revisions: Patrick McCleskey, MD, FAAD. Last revised April 2011.

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References Berger T, Hong J, Saeed S, Colaco S, Tsang M, Kasper R. The Web-Based

Illustrated Clinical Dermatology Glossary. MedEdPORTAL; 2007. Available from: www.mededportal.org/publication/462.

Habif TP. Clinical Dermatology: a color guide to diagnosis and therapy, 4 th ed. New York, NY: Mosby; 2004.

Layton AM, Cunliffe WJ. Minocycline induced skin pigmentation in the treatment of acne—a review and personal observations. J Dermatol Treatment 1989;1:9-12.

Lio PA. Little white spots: an approach to hypopigmented macules. Arch Dis Child Pract Ed 2008;93:98-102.

Marks Jr JG, Miller JJ. Chapter 13. White Spots (chapter). Lookingbill and Marks’ Principles of Dermatology, 4th ed. Elsevier; 2006:187-197.

Wolverton SE. Systemic drugs for infectious diseases (Chapter 5) and Topical Antifungal Agents (Chapter 29). Comprehensive Dermatologic Drug Therapy, 2nd ed. Elsevier; 2007: 80-99, 547-559.