Dermatology

Question 1

What are the ABCDEs of melanoma?

Answer 1

• asymmetry
• border irregularities
• color irregularities
• diameter greater than 6mm
• evolution over time

Question 2

Describe the diagnosis and treatment of melanoma?

Answer 2

• only a full thickness biopsy is sufficient

- treat with excision including large margins

Question 3

Where does melanoma commonly metastasize to?

Answer 3

the brain

Question 4

What are risk factors for squamous cell carcinoma?

Answer 4

• sun exposure
• transplant/chronic immunosuppression
• chronic irritation (e.g. scar, wound, etc.)

Question 5

How is basal cell carcinoma biopsied?

Answer 5

a shave biopsy is acceptable and full thickness biopsy isn’t required

Question 6

What is the benefit of Mohs surgery?

Answer 6

it permits removal of basal cell carcinoma with the loss of only the smallest amount of normal tissue

Question 7

Describe the etiology, presentation, and treatment of Kaposi sarcoma.

Answer 7

• due to HHV-8
• presents as reddish/purplish lesions on the skin but are also found in the GI tract and lung of those with a CD4 count less than 100
• treat with HAART therapy and the lesions will resolve as the CD4 count rises; otherwise, vincristine or interferon injections are helpful

Question 8

Describe the presentation, malignant potential, and treatment of actinic keratoses.

Answer 8

• present as rough, scaly lesions that appear as if they may ulcerate
• they are premalignant with a small risk for transformation into squamous cell carcinoma, so must be treated
• use curettage, cryotherapy, laser ablation, topical 5-FU, or imiquimod

Question 9

What is imiquimod?

Answer 9

a local immunostimulant used to treat actinic keratoses, molluscum contagious, and condyloma acuminata

Question 10

Describe the presentation, malignant potential, and treatment of seborrheic keratoses.

Answer 10

• these are hyperpigemented lesions with a stuck on appearance
• they carry no malignant potential so removal is only for cosmetic reasons

Question 11

Describe the pathophysiology, presentation, and treatment of eczema.

Answer 11

• also known as atopic dermatitis, it is associated with overactivity of mast cells and the immune system
• presents as an itch that rashes in those with a history of atopy; lesions are scaly, rough areas of thickened skin
• treat with skin moisturizers and avoidance of skin trauma or irritation which promote the itch-scratch cycle
• use steroids, tacrolimus and pimecroliumus, antihistamines, and phototherapy for medical management

Question 12

What is Tacrolimus?

Answer 12

a T cell inhibiting agent

Question 13

Describe the presentation and treatment of psoriasis.

Answer 13

• presents as non-pruritic, silvery, scaly plaques
• treat local disease with steroids, vitamin A and vitamin D ointment, coal tar preparation, and tacrolimus or pimecroliumus
• treat extensive disease with phototherapy, TNFa inhibitors, and methotrexate (last resort due to toxicity)

Question 14

What skin condition is described as diffuse erythematous macular lesions that spare the palms and soles and is preceded by a herald patch? How is it treated?

Answer 14

• this is pityriasis rosea

- it is self-limited but can be treated with steroids or phototherapy

Question 15

Describe the pathophysiology and treatment of seborrheic dermatitis.

Answer 15

• it is a hypersensitivity reaction to dermal infection with noninvasive dermatophytes
• treat with steroids and antifungals

Question 16

With which medications is drug-induced pemphigus vulgaris associated?

Answer 16

primarily ACE inhibitors as well as pencillamine, penicillin, and phenobarbital

Question 17

Compare and contrast pemphigus vulgaris and bullous pemphigoid.

Answer 17

• vulgaris involves bullae that easily rupture and involve the mouth and is characterized by a positive Nikolsky sign
• bullous pemphigoid is much milder with intact bullae, no mucosal involvement, and a negative Nikolsky sign
• furthermore, bullous pemphigoid has a linear deposition of IgG whereas vulgaris has a net-like distribution

Question 18

How are pemphigus vulgaris and bullous pemphigoid diagnosed and treated?

Answer 18

• for both, biopsy and immunofluorescence is the most accurate test
• vulgaris is treated with steroids, azathioprine, mycophenolate, and sometimes IVIG or rituximab
• bullous pemphigoid responds to these but more mild cases can be treated with dapsone or nicotinamide

Question 19

Describe the pathophysiology, presentation, diagnosis, and treatment of porphyria cutanea tarda.

Answer 19

• caused by a uroporphyrin decarboxylase deficiency
• presents with blistering of sun-exposed areas, particularly the back of the hands, in those with hepatitis C, estrogen use, and iron overload
• the most accurate test is an elevated 24-hour urine uroporphyrin level
• treat the underlying condition, namely hepatitis C

Question 20

How is impetigo treated?

Answer 20

• mild disease is treated with topical mupirocin while more severe disease is treated with oral dicloxacillin or cephalexin
• if MRSA is suspected, use doxy, clinda, or bactrim

Question 21

Describe the pathophysiology, presentation, and treatment of erysipelas.

Answer 21

• due to an infection, usually Strep, of the deeper skin levels with invasion of the dermal lymphatics
• for this reason it produces a well-demarcated erythematous region of skin as well as systemic signs
• treat mild disease with oral methicillin or MRSA antibiotics; IV antibiotics are required for systemic illness including fever

Question 22

What is the difference between treating impetigo and cellulitis?

Answer 22

cellulitis is a deeper infection, thus topical antibiotics are insufficient

Question 23

What is unique about treating erysipelas versus other skin infections?

Answer 23

it has the potential to invade dermal lymphatics, so if systemic symptoms are present like fever, IV antibiotics are required

Question 24

What is the difference between folliculitis, furuncles, and carbuncles?

Answer 24

• folliculitis is a minor infection around a hair follicle
• furuncles are abscesses around a hair follicle
• carbuncles are collections of furuncles

Question 25

Describe the presentation, diagnosis, and treatment of tinea.

Answer 25

• presents as a pruritic, erythematous annular border with central scaling
• the best initial test is KOH prep and the most accurate is fungal culture
• the best initial therapy is a topical anti fungal; if hair or nails are involved use oral terbinafine

Question 26

What is the preferred treatment of oral and vaginal candidiasis?

Answer 26

both should be treated with topical antifungals such as clotrimazole or nystatin

Question 27

Describe the presentation and treatment of staphylococcal scalded skin and toxic shock syndromes.

Answer 27

• they both present with a rash similar to TEN including mucous membrane involvement and a positive Nikolsky sign
• toxic shock has additional multi organ involvement including hypotension, renal dysfunction, CNS involvement, and liver dysfunction
• treat with supportive care and antistaphylococcals

Question 28

Describe the progressive treatment of acne.

Answer 28

1. begin with topical antibacterials like benzoyl peroxide
2. add topical antibiotics clindamycin or erythromycin
3. add topical vitamin A derivatives
4. add oral antibiotics minocycline or doxycycline
5. add oral vitamin A in the form of isotretinoin