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Blotches:Dark 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 hyperpigmented rashes.

After completing this module, the medical student will be able to:• Identify and describe the morphology of common

hyperpigmented rashes• Provide an initial treatment plan for selected dark rashes• Determine when to refer a patient with a dark rash to a

dermatologist

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Case One

Scott Goff

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Case One: History

HPI: Scott Goff is a 28-year-old male who presents with “blotches” on his upper back and chest for several years. They do not cause any symptoms other than anxiety because he has these dark spots.

PMH: no major illnesses or hospitalizations Allergies: none Medications: protein supplements Family history: none Social history: accountant; weightlifter ROS: negative

Case One: Skin Exam

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Case One: Skin Exam

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Case One, Question 1

Mr. Goff’s chest shows hyperpigmented, scaly macules on his upper chest and back. Which is the best test to confirm the diagnosis?

a. Bacterial culture

b. Direct fluorescent antibody (DFA) test

c. Potassium hydroxide (KOH) exam

d. Wood’s light

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Case One, Question 1

Answer: c Mr. Goff’s chest shows hyperpigmented, scaly

macules on his upper chest and back. Which is the best test to confirm the diagnosis?

a. Bacterial culture

b. Direct fluorescent antibody (DFA) test

c. Potassium hydroxide (KOH) exam

d. Wood’s light

Case One, 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. Goff 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 One, Question 2

What is the best treatment for Mr. Goff?a. Ketoconazole shampoo

b. Narrow band UVB phototherapy

c. Oral griseofulvin

d. Tacrolimus cream

e. Triamcinolone cream

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Case One, Question 2

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

a. Ketoconazole shampoo

b. 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 One, Question 3

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

week of treatment

b. Oral azoles should be used in most cases

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

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Case One, Question 3

Answer: c Which of the following statements 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 Two

Melinda Kinsley

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Case Two: History

HPI: Melinda Kinsley is a 48-year-old Guatemalan woman who presents with ten years of dark spots on her face. She tried a bleaching cream she got from Mexico but her friend told her it could make the spots worse.

PMH: three normal pregnancies; s/p tubal ligation Allergies: none Medications: supplements black cohosh, evening

primrose Family history: noncontributory Social history: lives with husband and children ROS: negative

Case Two: Skin Exam

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Case Two, Question 1

Which of the following is most likely associated with this symmetric hyperpigmentation?

a. Ginseng

b. Limes

c. Minocycline

d. Malassezia furfur

e. Pregnancy

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Case Two, Question 1

Answer: e Which of the following is most likely associated

with this symmetric hyperpigmentation?a. Ginsengb. Limesc. Minocyclined. Malassezia furfure. Pregnancy

Melasma

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Melasma (aka Chloasma)

Melasma is characterized by patchy light to dark brown hyperpigmentation of the face

Usually affects women, runs in families Associated with hormonal changes

• Called the “mask of pregnancy”• May occur with pregnancy, birth control pills,

and hormone replacement therapy

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Melasma (aka Chloasma)

Worse with exposure to UV radiation Treatments

• Strict sun avoidance, daily sunscreen with broad spectrum coverage and SPF > 30

• Hydroquinone 4% cream BID• If this fails, may refer to dermatology for

cosmetic treatments like triple topical therapy, lasers, or chemical peels, but these will usually be at the patient’s expense

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Case Three

Henry Fontana

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Case Three: History

HPI: Henry Fontana is a 78-year-old man who presents with of darkening of his arms and neck over the past few years. He recently underwent knee replacement surgery, and the orthopedist noticed a greenish pigmentation of his bones.

PMH: hypertension, GERD, osteoarthritis, BPH, basal cell and squamous cell carcinomas, rosacea

Allergies: none Medications: atenolol, felodipine, celecoxib, oxybutinin,

rabeprazole, minocycline Family history: noncontributory Social history: widower; lives alone ROS: negative

Case Three: Skin Exam

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Case Three, Question 1

Which of the following medications is most likely associated with this pigmentation?

a. Atenolol

b. Celecoxib

c. Minocycline

d. Oxybutinin

e. Rabeprazole

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Case Three, Question 1

Answer: c Which of the following medications is most

likely associated with this pigmentation?a. Atenololb. Celecoxibc. Minocyclined. Oxybutinine. Rabeprazole

Minocycline pigmentation

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Minocycline pigmentation

Deposition appears after months to years in a small percentage of patients

First noticeable on the alveolar ridge, palate, sclera May involve bones, thyroid, but this is harmless Skin deposition can be brown or blue-grey Blue-grey pigmentation may occur in scars Skin pigmentation may not fade after discontinuation Patients on long-term minocycline should be

screened; if seen on gums or sclerae, discontinue33

Other causes of medication-related hyperpigmentation

Amiodarone Antimalarials

• Hydroxychloroquine• Chloraquine

Calcium channel blockers• Verapamil• Diltiazem

Zidovudine Imipramine

• Some antipsychotics

Some chemotherapy agents34

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Case Four

Elaine Gosnel

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Case Four: History

HPI: Elaine Gosnel is a 66-year-old woman with a two-year history of an itchy rash on her legs that has resulted in dark spots.

PMH: hypertension, diabetes, hyperlipidemia Allergies: none Medications: metoprolol, simvastatin, metformin Family history: noncontributory Social history: widowed; lives in a retirement

community ROS: edematous legs

Case Four: Skin Exam

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Case Four, Question 1

The patient’s legs show scaly brown plaques on her lower legs bilaterally. Pedal pulses are normal. What is the most likely diagnosis for Mrs. Gosnel’s rash?

a. Atopic dermatitis

b. Erysipelas

c. Irritant contact dermatitis

d. Stasis dermatitis

e. Tinea corporis

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Case Four, Question 1

Answer: d The patient’s legs show scaly brown plaques on her

lower legs bilaterally. Pedal pulses are normal. What is the most likely diagnosis for Mrs. Gosnel’s rash?

a. Atopic dermatitis (wrong location, no history)b. Erysipelas (usually unilateral, acute not chronic)c. Irritant contact dermatitis (not good location, no

history)d. Stasis dermatitise. Tinea corporis (more superficial)

Stasis dermatitis

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Case Four, Question 2

You correctly diagnose Mrs. Gosnel with stasis dermatitis. What do you recommend?

a. Bacitracin ointment twice daily

b. Daily oral trimethoprim-sulfamethoxazole

c. Debridement of superficial erosions

d. Elevation and compression stockings

e. Immediate referral to vascular surgery

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Case Four, Question 2

Answer: d You correctly diagnose Mrs. Gosnel with stasis

dermatitis. What do you recommend?a. Bacitracin ointment twice daily (likely to cause allergic

contact dermatitis)b. Daily oral trimethoprim-sulfamethoxazole (no active

infection)c. Debridement of superficial erosions (may worsen)d. Elevation and compression stockings e. Immediate referral to vascular surgery (not indicated

for most stasis dermatitis)

Stasis dermatitis

Venous stasis dermatitis is an eczematous eruption that occurs in venous insufficiency and leg edema• Acute eczematous dermatitis (itchy red scaly plaques)

leads to chronic eczematous dermatitis; may be weepy• Extravasation leads to brown pigmentation and

petechiae• Venous ulcers may result, especially on medial

malleolus

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Refer to the module on Stasis Dermatitis and Leg Ulcers for more information

Stasis dermatitis: Treatment

Reduce edema with elevation and compression stockings

Wet compresses may aid in healing erosions or ulcers

Mid-potency topical steroids control inflammation

Avoid topical antibiotics because up to half develop allergic contact dermatitis, especially to neomycin and bacitracin

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Quick Case: Dark spot on the leg

This 32-year-old man who had a small laceration two years ago and presents with a dark spot

He’s worried it might be something bad

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Quick Case: Diagnosis?

What is the most likely diagnosis?a. Drug-induced

pigmentation

b. Melanoma

c. Postinflammatory hyperpigmentation

d. Post-traumatic fungal infection

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Quick Case: Diagnosis?

Answer: c What is the most likely

diagnosis?a. Drug-induced

pigmentation

b. Melanoma

c. Postinflammatory hyperpigmentation

d. Post-traumatic fungal infection

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Postinflammatory hyperpigmentation

Postinflammatory hyperpigmentation describes a common phenomenon of darkening of the skin at or around sites of injury or inflammation

• Individuals with olive or slightly darker complexion are at particular risk

• The pigmentation takes months to years to fade but usually improves gradually over time

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Postinflammatory hyperpigmentation

Reassure patients this is normal• This is not a scar; it’s just increased

pigment• Use sunscreen after injuries or surgical

procedures• For significant or problematic

hyperpigmentation, refer to a dermatologist

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Postinflammatory hypopigmentation

Some patients heal with light spots instead

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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Common dark rashes

Tinea versicolor Melasma Drug pigmentation Stasis dermatitis Postinflammatory hyperpigmentation

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Take Home Points: Dark Rashes

Tinea versicolor may be hyperpigmented Symmetric brown patches on the zygomatic, buccal,

and mandibular cheeks of adult women are usually melasma

Some medications (especially minocycline) cause hyperpigmentation; warn patients and monitor for it

Venous stasis can cause hyperpigmentation Postinflammatory hyperpigmentation and

hypopigmentation are very common in darker skin types, so treat skin conditions aggressively 52

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 2011.53

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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, 4th 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.