Dermatologic

Question 1

What is required to diagnosis cellulitis?

Answer 1

It’s a clinical diagnosis. Cultures not required because often negative. Should see warmth, swelling, tenderness, erythema in a rapidly-demarkated but rapidly growing area. +/- lymphatic streaking, +/- fever and chills

Question 2

What is the #1 cause of cellulitis?

Answer 2

staph aureus or group A strep

Question 3

What is treatment of cellulitis based on?

Answer 3

Largely based on the risk of MRSA infection

Question 4

What does the skin look like in allergic contact dermatitis? What are differences between this and cellulitis?

Answer 4

Skin: itchy, red, edematous, weepy, crusted, +/- vesicles or bullae

Differences:

1. Allergic contact dermatitis is itchy and cellulitis is not
2. Cellulitis somestimes has fever, allergic contact dermatitis pretty much never does

Question 5

How can you distinguish venous stasis dermatitis from cellulitis?

Answer 5

Venous stasis is bilateral, no fever/leukocytosis, and often has hyperpigmentation due to hemosidern deposition.

Also, venous stasis dermatitis usually is painless

Question 6

Recurrent itchy, red rash on the eyebrows and cheeks. No fever. Diagnosis?

Answer 6

Seborrheic dermatitis. Classically affects the scalp and face because those places have a lot of sebaceous glands. Especially likes eyebrows, eyelids, external auditory canals, nasolabial folds, cheeks.

Question 7

How do you treat seborrheic dermatitis?

Answer 7

Low potency steroids
Ketoconazole cream
Shampoos with tar, ketoconazole, selenium (scalp)

Question 8

How is rosacea different from seborrheic dermatitis?

Answer 8

1. Rosacea is usually really the cheeks and nose… seborrheic dermatitis can be these areas but also likes eyelids, forehead, ears
2. Rosacea has telangectasias, pusutles, papules and seborrheic dermatitis is mostly greasy scales and crusts that itch

BIGGEST DIFFERENCE: Rosacea has pustules

Question 9

How do you distinguish between rosacea in its early stages (no pustules yet, just facial erythema) and SLE rash?

Answer 9

SLE rash usually spares the nasolabial folds and chin, rosacea does not

Question 10

What does dermatomyositis look like?

Answer 10

Heliotrope rash: Purple-dusky-red around the eyes
Gottron papules: Elevated, scaly, purple papules and plaques over bony prominences and especially the hands

Also shawl-shaped rash around the shoulders

Question 11

Groin rash for >1 yr (not itchy) with concomittant scaling on sides of feet. Diagnosis?

Answer 11

Tinea cruris. Definition is that it involves the groin, pubic region, inner thighs

Question 12

What does tinea cruris look like?

Answer 12

“active” (red) border with central clearing. Localized to genital area (groin, inner thighs)

Question 13

What does genital candida look like?

Answer 13

Often involves scrotum (unlike tinea cruris). Starts out as pustules then becomes confluent patch with satellite lesions

Question 14

What can cause SJS?

Answer 14

• Antibiotics (especially TMP/SMX)
• Antiepileptics (like lamictal)
• Allopurinolq

Question 15

What is erythema multiforme?

Answer 15

Targetoid lesions often involving skin and mucus membranes. 90% associated with infectious (usually HSV), but sometimes drugs or idiopathic. Involves the palms. Often get red papules, vesicles, bullae.

Question 16

What is erythema migrans?

Answer 16

Hallmark of early lyme disease. Centrifugally spreading ring of erythema that looks like a bulls eye. Starts 3-30 days after tick bite. Usually on the armpit, back of knee, groin, belt line

Question 17

How do you distinguish erythema multiforme (rash usually associated with HSV) from erythema migrans (rash usually associated with lyme disease)?

Answer 17

1. Size (lyme disease/migrans is usually big)

2. Location (lyme disease/migrans usually doesnt involves palms or mucus membranes)

Question 18

How does RMSF present?

Answer 18

fine, pink, BLANCHING macules and papules on the wrists and ankles that spread both inwards (to torso) and outwards (to palms and soles)

Question 19

What rashes are associated with strep infection?

Answer 19

• Erythema nodosum (also seen with IBD. On shins)
• Psoriasis flares
• Cellulitis
• Dactylutis

Question 20

How do you treat shingles (herpes zoster)?

Answer 20

Oral famciclovir *memory: Think of a FAMILY getting shingles

Can also use acyclovir or valcyclovir

Question 21

How soon do you have to give acyclovir/valcyclovir/famciclovir in order for it to be helpful for shingles?

Answer 21

Within 72 hours of onset of rash

If you do this, it will decrease postherpetic neuralgia, decrease pain, AND accelerate healing

Question 22

Are steroids used in the treatment of shingles?

Answer 22

Yes. Help accelerate healing, decrease pain, decrease insomina, etc.

But the MAIN treatment is acyclovir/valcyclovir/famcyclovir (oral). Mostly because steroids do NOT improve postherpetic neuralgia

Question 23

When would you use IV acyclovir instead of oral famciclovir or valacyclovir for treatment of shingles?

Answer 23

• Severe herpes zoster ophthalmicus

- CNS symptoms

Question 24

Which medications make acne worse?

Answer 24

steroids (testosterone, danazol)
corticosteroids
isoniazid
lithium
phenytoin

Question 25

How do you treat noninflammatory acne (blackheads)?

Answer 25

benzoyl peroxide
salicylic acid
acelaic acid
retinoids

Question 26

How do you treat mild inflammatory acne (white heads, few papules and pustules)?

Answer 26

topical comedolytic agents

topical antibiotic

Question 27

When is oral antibiotics first line for acne?

Answer 27

severe inflammatory acne; cystic and pusutlar lesions are extensive

Question 28

When is isotretinoin first line for acne?

Answer 28

Never. Only indicated for those unresponsive to oral antibiotics.

Question 29

What are side effects of isotretinoin?

Answer 29

hyperTG
pseudotumor cerebri
decreased BMD
depression and psychosis

Question 30

What defines acute vs chronic urticaria?

Answer 30

Lasting less vs. more than 24 hours

Question 31

What % of patients with RMSF have the blanching macules on the wrists?

Answer 31

90%

Question 32

12 yr old boy back from summer camp with linear rash with excoriations- tx?

Answer 32

Topical steroids. Treat for poison ivy.

Question 33

How to treat tinea capitis?

Answer 33

Oral griseofulvin

Question 34

Which fungal infections usually require oral (not topical) antifungal treatment?

Answer 34

scalp infections (tinea capitis) and nail infection (onychomycosis)

Question 35

What is acral lentiginous melanoma?

Answer 35

Acral lentiginous melanoma is seen more often in dark-skinned people, and typically appears on the palms and soles of feet, including under the nails.