Dermatology

Question 1

%BSA for SJS vs. TEN

severity scoring system

Answer 1

10% or less = SJS
10-30% = overlap
>30% = TEN

SCORTEN is a severity-of-illness score validated for TEN. It incorporates blood Sugar (plasma glucose level >252 mg/dL [14.0 mmol/L]), presence of Cancer, Older age (>40 years), heart Rate (>120/min), Ten percent or more body surface area involvement on day 1, Electrolytes (serum bicarbonate <20 mEq/L [20 mmol/L]), and blood urea Nitrogen (>28 mg/dL [10 mmol/L]). Mortality is directly correlated with the number of SCORTEN variables that are fulfilled.

Question 2

(1) morbiliform drug eruption VS. (2) DRESS

Answer 2

(1) - occurs 4-14 days after drug initiation, no systemic involvement, can have peripheral eos
(2) - occurs 2-6 weeks after drug initiation, peripheral eos, but also usu have skin pain, elevated LFTs, facial swelling

Question 3

what type of phototherapy is used in extensive psoriasis?

Answer 3

Narrowband ultraviolet B (UVB)

Question 4

describe rash of erythema nodosum and if found what further workup should be pursued ? what are some other causes?

Answer 4

1 - location on bilateral anterior shins, nodular, pink-red-brown
2 - get CXR! to evaluate for sarcoidosis, lymphoma, TB, or fungal infection such as coccidioidomycosis

It can also be caused by strep infection, IBD, or reaction to meds hormonal - esp OCP

Question 5

How do you treat dermatitis herpetiformis? what is classically found on skin biopsy?

Answer 5

Dapsone + gluten-free diet

Deposition of granular IgA in the dermal papillary tips (pathognomonic)

Question 6

First line treatment in comedonal acne?

Answer 6

Topical retinoids (because they are comedolytic and normalize keratinization of the hair follicle)

Question 7

Porphoria Cutanea Tarda

1. explain appearance and progression
2. cause/pathophys
3. Causes/etiology
4. Diagnosis
5. Treatment

Answer 7

1 – Milia, small epidermal inclusion cysts that develop after subepidermal blister formation. As the disease progresses, hyperpigmentation of skin and hypertrichosis of the forehead/temples is commonly seen. Jaundice may be present.
2 – acquired defect of hepatic uroporphyrinogen decarboxylase (UPDC) enzyme –> results in the accumulation of porphyrinogens that are oxidized to porphyrin–> are photosensitizing and when they are transported to the skin cause phototoxicity on light exposure.
3 – Chronic hepatitis C infection, or alcohol-induced liver damage, or hemochromatosis.
4 – Urine exam under Wood lamp illumination will fluoresce. Can confirm with increased plasma or urine porphyrin level analysis.
5 – decreasing iron overload. In addition to treating the underlying condition (phlebotomy) Low-dose hydroxychloroquine is an effective second option for those who do not have significant iron overload. It is dosed at 200 mg once or twice weekly.

Question 8

Name 4 medications/classes that can cause generalized pruritis without skin findings

Answer 8

Hydrochlorothiazide
calcium channel blockers
opiates
NSAIDs

Question 9

What is Vismodegib

Answer 9

oral medication that inhibits the hedgehog signaling pathway (this signaling pathway is aberrant in most basal cell carcinomas). It is reserved for locally advanced or metastatic basal cell carcinomas.

Question 10

What is amyloid light chain amyloidosis? clinical manifestations? what are skin manifestations?

Answer 10

1 – MC type of amyloidosis; it is a plasma cell dyscrasia-related disease characterized by end-organ damage secondary to tissue deposition of monoclonal free λ or κ light-chain fibrils.
2 – poteinuria with worsening kidney function, restrictive cardiomyopathy, and hepatomegaly. Bleeding from factor X deficiency.
3 – Skin manifestations present in 30-40% of patients and include generalized waxy appearance, ecchymoses with minor pressure (“pinch purpura”), ecchymoses around the eyes (“raccoon eyes”), yellow waxy papules and plaques especially in a periorbital location, dystrophic nails, and macroglossia.