Benign Skin LesionsMedical Student Core Curriculum in

Dermatology

Updated August 14, 20111

Goals and Objectives

Goal: the purpose of this module is to help medical students recognize and manage some of the most common benign skin lesions

Learning Objectives: by completing this module, the learner will be able to: 

• Recognize some of the most common benign skin lesions

• Educate a patient about these lesions• Discuss management options of these lesions as

appropriate

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Case One

A 42-year-old white male presents with a “new mole” on his back, first noticed by his wife 4 months ago.

The lesion sometimes itches and it bled once after getting caught on his shirt.

“Doc, do I have skin cancer?”

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This lesion is best described as:

a) Pigmented and smooth

b) Pigmented and stuck-on

c) Skin-colored and exophytic

d) Skin-colored and waxy

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This lesion is best described as:

a) Pigmented and smooth

b) Pigmented and stuck-on

c) Skin-colored and exophytic

d) Skin-colored and waxy

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What is the diagnosis?

a) Melanoma

b) Nevus (mole)

c) Seborrheic keratosis

d) Verruca (wart)

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What is the diagnosis?

a) Melanoma

b) Nevus (mole)

c) Seborrheic keratosis

d) Verruca (wart)

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Seborrheic keratosis

Seborrheic keratosis Benign superficial

(epidermal) growth Common after age 30 Can arise on all body

surfaces except palms and soles

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Seborrheic keratoses (SKs)

Often multiple & can be extensive Individual lesions do not go away SKs begin to appear during and

after the fourth decade and continue to arise throughout life

Contrast this with nevi, which typically appear in the first three decades of life • A new nevus at age 50 should

raise suspicion of melanoma...

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Seborrheic Keratoses

Color can vary from black to tan to white to pink… Texture can vary from velvety to verrucous (wart-

like)…

Velvety, dark brown Verrucous, tan10

Light tan or almost skin colored

How can I tell if a lesion is a seborrheic keratosis?

SKs are superficial epidermal growths. They always have a stuck-on quality, like a glob of wax smushed onto the skin.

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How can I tell if a lesion is a seborrheic keratosis?

If you are in doubt of the diagnosis, try gently picking at or scratching the lesion. It may crumble, flake, or lift off, revealing that superficial waxy character.

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How can I tell if a lesion is a seborrheic keratosis?

Also, take a look around at the patient’s other growths – Does the lesion look like it’s neighbors?

Always pay attention to “the ugly duckling” – the lesion that appears different from the rest.• When in doubt, biopsy or refer.

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Seborrheic keratoses

Though harmless, SKs can occasionally become irritated or can be cosmetically bothersome

When necessary, SKs may be curetted, lightly frozen or electrodessicated

If picked off or curetted, SKs will leave a pink moist base with minimal bleeding

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Seborrheic keratoses

This SK has been partially picked off

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“Doc, can you remove my freckles?”

Are these freckles? No, they are tiny SKs. Dermatosis papulosa

nigra• Arise in darker skin types,

usually on the cheeks and temples

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Dermatosis papulosa nigra

Harmless, but a cosmetic issue for some “Doc, can you freeze these off for me?”

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Dermatosis papulosa nigra

Why not liquid nitrogen?• Freezing could cause unsightly hypopigmentation

– Melanocytes are very sensitive to cold

Which “treatment” might you choose?• Very light electrodessication

is often safest (use of electric current to cause superficial destruction)

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This woman had SKs frozen off and now has permanent dyspigmentation

Even with electrodessication, a test spot is in order to determine how the patient is likely to react

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Another variant of SKs…

Stucco keratoses – small white-gray SKs pepper dorsal feet and ankles of older fair-skinned individuals

Again, harmless, but if desired, may: freeze, curette, or electrodessicate

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Case Two

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“Doc, these ‘moles’ keep getting caught on my necklaces. Can you remove them?”

Skin tags (acrochordons)

Acrochordons: fleshy papules arise in axillae, neck, groin, and eyelids

Skin colored to brown Often pedunculated

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“Doc, why do I get these skin tags?”

Genetics, obesity, friction may all play a role.

Like acanthosis nigricans, skin tags can be a marker for insulin resistance.

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Back to our original patient

She asks for cosmetic removal.

You ascertain that her mother has diabetes.

What lab test might you consider for her?• Fasting blood glucose

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Skin tag removal is elective

Methods for elective removal include: • Snipping (use pressure or aluminum

chloride for any bleeding)• Liquid nitrogen (for lighter skin

types)• Electrodessication

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Occasionally skin tags will outgrow their blood supply or become torsed such that they necrose and fall off on their own

Case Three

A 45-year-old white male presents with a “red mole” which appeared 6 months ago and has increased in size.

It is not tender and has not bled.

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What is the diagnosis?

a) Angioma

b) Basal cell carcinoma

c) Melanoma

d) Nevus (mole)

e) Seborrheic keratosis

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What is the diagnosis?

a) Angioma

b) Basal cell carcinoma

c) Melanoma

d) Nevus (mole)

e) Seborrheic keratosis

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What do you do?

a) Biopsy immediately

b) Perform a workup for internal malignancy

c) Reassure him that it is harmless, will not go away, and that he is likely to get more over the years

d) Reassure him that it will go away

e) Refer to dermatology

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What do you do?

a) Biopsy immediately

b) Perform a workup for internal malignancy

c) Reassure him that it is harmless, will not go away, and that he is likely to get more over the years

d) Reassure him that it will go away

e) Refer to dermatology

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Cherry angiomas

Cherry angioma Majority of people

get these starting around age 30

Highest concentration on the trunk

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“When in doubt, cut (or refer) it out”

Traumatized cherry

Occasionally cherry angiomas may bleed or thrombose, thereby mimicking melanoma

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Case Four

A 24-year-old female reports developing a new growth on her leg 6 months ago.

She sometimes nicks it when shaving.

It’s gotten darker around the edges over the past few months.

On palpation, you notice that it feels firm, like scar tissue.

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What is the diagnosis?

a) Basal cell carcinoma

b) Dermatofibroma

c) Melanoma

d) Nevus

e) Seborrheic keratosis

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What is the diagnosis?

a) Basal cell carcinoma

b) Dermatofibroma

c) Melanoma

d) Nevus

e) Seborrheic keratosis

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What do you do?

a) Biopsy immediately

b) Reassure the patient that it is benign but it won’t go away

c) Reassure the patient that it will go away

d) Refer to dermatology

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What do you do?

a) Biopsy immediately

b) Reassure the patient that it is benign but it won’t go away

c) Reassure the patient that it will go away

d) Refer to dermatology

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Dermatofibroma

Firm, scar-like texture, in combination with history, is the give-away clue to diagnosis

Peripheral rim of darkening pigment is common

Dermatofibroma This benign spindle cell dermal proliferation looks like

wad of scar tissue under the microscope –

hmm, just like it feels…

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Dermatofibroma

If you pinch on either side of a dermatofibroma, it tends to dimple down due to that scar-like tethering of the dermis - “the dimple sign”

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“Doc, why did I get this?”

Often on the legs, especially women

Can be multiple Possibly due to minor

unrecognized skin insults

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Case Five

A 65-year-old woman complains of “ugly brown spots” on her face and dorsal hands which she feels makes her “look old”

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What is the diagnosis?

a) Café au lait macules

b) Liver failure

c) Metastatic melanoma

d) Solar lentigines

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What is the diagnosis?

a) Café au lait macules

b) Liver failure

c) Metastatic melanoma

d) Solar lentigines

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What will you tell the patient?

The solar lentigo, AKA “sun spot”, “age spot”, or “liver spot” is due to sun damage, but is not cancerous or precancerous

No treatment required, however…

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• Extensive solar lentigines reflect history of UV exposure, and therefore can identify patients at risk for skin cancer

Solar Lentigines

Although no treatment is required, there are a variety of cosmetic treatments available (bleaching creams, liquid nitrogen, chemical peels, lasers…)

The first step is always sun protection

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“Doc, how can I tell the difference between one of these lentigines and melanoma?”

Look for the ugly duckling Consider biopsy or referral to a dermatologist for

any lesion that stands out as different Recall the ABCDE’s

– Asymmetry– Border (irregular)– Color (multiple, variegated)– Diameter (>6mm)– Evolving

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Case Six

A 57-year-old female presents with numerous, asymptomatic bumps on her face, slowly arising over the past 5 years

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Skin Exam

How would you describe these lesions?a) Erythematous

eczematous plaques

b) Erythematous edematous plaques

c) Pigmented waxy papules

d) Skin-colored smooth papules

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Skin Exam

How would you describe these lesions?a) Erythematous

eczematous plaques

b) Erythematous edematous plaques

c) Pigmented waxy papules

d) Skin-colored smooth papules

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Diagnosis

What is the diagnosis?a) Basal cell carcinomas

b) Nevi

c) Sebaceous hyperplasia

d) Seborrheic keratoses

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You observe numerous skin-colored or slightly yellow, umbilicated (i.e. have a central dell) papules on forehead and central face.

Diagnosis

What is the diagnosis?a) Basal cell carcinomas

b) Nevi

c) Sebaceous hyperplasia

d) Seborrheic keratoses

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You observe numerous skin-colored or slightly yellow, umbilicated (i.e. have a central dell) papules on forehead and central face.

a) Expect more of these in coming years

b) Shave biopsy is necessary to rule out early skin cancers (basal cell carcinoma)

c) Use a face wash for oily skin to reduce the appearance of these

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What do you tell the patient?

a) Expect more of these in coming years

b) Shave biopsy is necessary to rule out early skin cancers (basal cell carcinoma)

c) Use a face wash for oily skin to reduce the appearance of these

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What do you tell the patient?

Sebaceous hyperplasia

Sebaceous hyperplasia Sebaceous gland (i.e. oil

gland) overgrowth• Hence the yellow color• Umbilication due to gland

growth around a central hair follicle

Removal is not medically required and is cosmetic

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Sebaceous Hyperplasia vs. BCC

How can you tell the difference between sebaceous hyperplasia and basal cell carcinoma, which can both look like skin colored papules on the face?• Yellow color, umbilication, and multiple

similar papules help identify sebaceous hyperplasia

• BCC tends to be solitary and more friable (bleeds, scabs) – also more pearly translucent, often with telangiectasia

• Biopsy or referral may be necessary

Sebaceous hyperplasia

Basal cell carcinoma55

Case Seven

A healthy 24-year-old African American male presents with an itchy, firm growth on the shoulder, which arose (gradually increasing in size) over several months after receiving the smallpox vaccine at this site

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What is the diagnosis?

a) Allergic reaction to the smallpox vaccine

b) Epidermal inclusion cyst

c) Foreign body granuloma

d) Keloid

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What is the diagnosis?

a) Allergic reaction to the smallpox vaccine

b) Epidermal inclusion cyst

c) Foreign body granuloma

d) Keloid

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What do you advise?

a) Apply topical hydrocortisone for the itch

b) Excise it for cosmesis

c) Excise it to ensure there is no foreign body

d) Inject it with steroid

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What do you advise?

a) Apply topical hydrocortisone for the itch

b) Excise it for cosmesis

c) Excise it to ensure there is no foreign body

d) Inject it with steroid

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Keloids

Keloid: overgrowth of scar tissue beyond the original scar site

Genetic influence (most common in African-Americans), also more common on upper trunk and earlobes

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Keloids

Can be itchy or tender Can be cosmetically

disfiguring “Doc, can’t you please

just cut this off?”

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Keloids

Excision alone is a bad idea! • Expect the keloid to recur,

even larger

Topical steroid is usually ineffective

Intralesional steroid and/or referral is best

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Case Eight

A 35-year-old male presents with a 1.5 cm nodule on the upper back and the chief complaint, “Doc, my wife keeps trying to pop this ‘sebaceous cyst’, but it just refills with nasty-smelling white material.”

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What is the diagnosis?

a) Basal cell carcinoma

b) Epidermal inclusion cyst

c) Sebaceous hamartoma

d) Smoldering abscess

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What is the diagnosis?

a) Basal cell carcinoma

b) Epidermal inclusion cyst

c) Sebaceous hamartoma

d) Smoldering abscess

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Epidermal Inclusion Cyst (EIC)

EIC: mobile subcutaneous nodule, often with an overlying punctum

Although sometimes referred to as “sebaceous cysts”, EIC’s actually arise from hair follicles, not oil glands

Debris (dead skin cells, oil, etc.) collects within a sack• May discharge foul smelling cheesy white material

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Which of the following would you tell the patient?

a) Advise him to keep “popping it” whenever possible to keep it small

b) Advise warm compresses until the cyst ruptures and clears

c) Tell the patient the only way to be rid of the lesion is complete surgical excision

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Which of the following would you tell the patient?

a) Advise him to keep “popping it” whenever possible to keep it small

b) Advise warm compresses until the cyst ruptures and clears

c) Tell the patient the only way to be rid of the lesion is complete surgical excision

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Epidermal Inclusion Cyst

Benign and require no treatment However, when traumatized, EICs may rupture in

the skin, creating an abscess which may require incision & drainage (I&D)

Unlike a bacterial abscess, ruptured EICs tend to be sterile and do not require oral antibiotics. Presence of a preceding EIC differentiates from bacterial abscess. Both types of abscesses require I&D.

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Case Nine

“Doc, this white bump on my cheek came up a few months ago and won’t go away. Is it cancer?”

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Diagnosis

Milia = tiny epidermoid cyst

Often on the face and therefore cosmetic concern

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What will you tell the patient?

a) It can be easily extracted without scarring

b) Just wait for it to go away on its own; we see this in newborns all the time

c) Pop it like a zit

d) The only treatment is surgical and the scar would be worse than the milia

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What will you tell the patient?

a) It can be easily extracted without scarring

b) Just wait for it to go away on its own; we see this in newborns all the time

c) Pop it like a zit

d) The only treatment is surgical and the scar would be worse than the milia

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Will milia go away on their own?

Nearly half of newborns have a few milia, and these DO tend to resolve, but when milia arise on the adult face, they will often persist

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MiliaElective removal for cosmesis

Nick the surface with an 11 blade or an 18 gauge needle, then gently express the entire cyst, lining and contents. Dress with a dab of petrolatum.

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Case Ten

“Doc, my wife says I’m growing horns. What are these things?”

Slowly enlarging over months to years

Firm, mobile subcutaneous nodules, lacking punctum

Do not discharge any material

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Pilar cysts

Pilar cysts Compared to an

EIC, less likely to rupture or get inflamed

Nearly always on the scalp

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Pilar cystsElective treatment is excision

Incise the overlying skin, dissect out and express the glistening, firm, white pilar cyst, and sew the defect closed.

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Case Eleven

“This lump has been slowly enlarging for years. It doesn’t bother me, but my wife wants it checked out.”

You palpate a mobile, soft, subcutaneous nodule, lacking any overlying skin change

On exam, he has a few other similar soft to rubbery mobile subcutaneous nodules on his arms and legs

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What do you tell the patient?

a) Treatment is surgical and completely elective

b) We need to excise quickly before this grows any bigger

c) We need to excise quickly to rule out metastatic cancer

d) You are likely to get many more of these in coming years

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What do you tell the patient?

a) Treatment is surgical and completely elective

b) We need to excise quickly before this grows any bigger

c) We need to excise quickly to rule out metastatic cancer

d) You are likely to get many more of these in coming years

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Lipoma

Texture is your clue – lipomas feel like what they are…collections of fat under the skin

Growth usually stabilizes at a few cm diameter

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Lipoma

Often solitary, frequently on the trunk and proximal extremities

When familial (autosomal dominant), lipomas tend to be multiple and begin in early adulthood

Occasionally lipomas can be tender

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Take Home Points:mix and match self quiz

Waxy, crumbly, stuck-on Superficial bright red

vascular papule Firm papule on the leg with

rim of pigmentation Definitive treatment for

epidermal inclusion cysts Elective removal of benign

lesions in darker skin types (DPN, skin tags, etc.)

Dermatofibroma Excision (NOT aspiration

or squeezing / “popping”)

Seborrheic keratoses Cherry angioma Electrodessication or

snip (NOT liquid nitrogen)

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Take Home Points:mix and match self quiz

Waxy, crumbly, stuck-on Superficial bright red

vascular papule Firm papule on the leg

with rim of pigmentation Definitive treatment for

epidermal inclusion cysts Elective removal of benign

lesions in darker skin types (DPN, skin tags, etc.)

Dermatofibroma Excision (NOT

aspiration or squeezing / “popping”)

Seborrheic keratoses Cherry angioma Electrodessication or

snip (NOT liquid nitrogen)

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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: Rebecca B. Luria, MD, FAAD. Peer reviewers: Susan K. Ailor, MD, FAAD;

Jennifer Swearingen, MD, Timothy G. Berger, MD, FAAD.

Revisions: Rebecca B. Luria, MD, FAAD; Sarah D. Cipriano, MD, MPH. Last revised August 2011.

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Suggested Readings/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.

Wolff K, Goldsmith LA, Katz SI, Gilchrest B, Paller AS, Leffell DJ: Fitzpatrick's Dermatology in General Medicine, 7th ed. New York, McGraw-Hill; 2008.

Marks, JG., Miller, JJ. Lookingbill and Marks' principles of dermatology. Philadelphia, PA: Saunders Elsevier; 2006.

Frankel DH Field Guide to Clinical Dermatology. 2nd ed. Philadelphia, PA : Lippincott Williams & Wilkins; 2006.

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