Tuesday - Westra - Accute inflammatory dermatosis

Question 1

What is a langerhan’s cell

Answer 1

A dendritic cell of the epidermis

Question 2

Urticaria

Answer 2

Transient wheals, <24 hours, usually IgE and histimine mediated , pruritic (itchy)

Question 3

Angioedema. when is it an emergency?

Answer 3

Deep dermal and subcutaneous swelling (usually IgE and histimine mediated).
painful more than it is pruritic.
Laryngeal involvement = emergency
Lip, eye, groin, palms, soles common.

Question 4

How often are urticaria and angioedema acute and chronic. What defines them as such?

Answer 4

Acute (2/3): duration < 6 weeks

Chronic (1/3): >6 weeks. usually idiopathic

Question 5

Physical urticaria causes

Answer 5

Sun (UV and visible light)
Cholinergic (sweating VS heat) - small papular urticaria after exercise.
Cold urticaria (begins during cold exposure, maximal upon rewarming)
Dermographism (friction)
Aquagenic
vibratory angioedema.

Question 6

Ways mast cells can be degranulated directly (non-immune)

Answer 6

Narcotics (MS and codeine)
Aspirin
NSAIDs
Radiocontrast media
Dextran
ACE inhibitor angioedema
Vancomycin - "Red Man" syndrome - flushing or hives after IV vanco.

Question 7

Foods that contain a high level of histamine

Answer 7

Strawberries
tomatoes
shrimp
lobster
cheese
spinach
eggplant

Question 8

What do you do if Urticaria and or angioedema lasts for >48 hours or looks atypical

Answer 8

Punch biopsy to exclude vasculitis.

Question 9

First choices of chronic urticaria Tx

Answer 9

Second - gen, non sedating H1 - blockers
Cetirizine (zyrtec)
Fexofenadine (allegra-D)
Desloratadine (clarinex)
Loratidine (claritin)

Question 10

Last resort for people with chronic urticaria

Answer 10

Oral corticosteroid (prednisone)

Question 11

Basic evals for a urticaria patient

Answer 11

CBC, ESR (ethryocyte sed rate), TSH (thyroid stimulating hormone), basic chemistry panel.

Question 12

Erythema multiforme. Most common where and in whom? What causes it?

Answer 12

common in extremities.
erythematous iris-shaped papular and veisculobullous lesions. not usually itchy.
50% are under 20 years, more frequent in males.

Causes: Sulfonamides, penicillin, dilantin, tegretol, herpes simplex virus, mycoplasma.

more than 50% of cases are idiopathic.

Question 13

EM minor

Answer 13

Erythema multiforme mild form, less than or equal to 1 mucosal site, major cause is post herpes simplex. EM occurs at day 10

Question 14

EM major

Answer 14

Severe with extensive skin and mucous membrane involvement (stevens johnson syndrome). Usually due to drugs (Sulfa, penecillin, dilantin, tegretol)

Question 15

Stevens johnson syndrome

Answer 15

Cytotoxic immune reaction aimed at destruction of keratinocytes expressing foreign (drug-related antigens

mucocutaneous drug-induced or idiopathic reaction patters. LOTS of erythemal patches. <10% epidermal detachment.

Question 16

Toxic epidermal necrolysis

Answer 16

Toxic epidermal necrolysis - maximal variant of SJS (could be a distinct disease), > 30% epidermal detachment, 2+ mucosal membrane.

Can be caused by sulfa drugs.

EMERGENCY

Question 17

Fixed drug eruption

Answer 17

A localized, sharply demarcated arythematous patch commonly on the face and genitals. Often heals as a hyperpigmented area

Question 18

Panniculitis

Answer 18

Inflamation of subcutaneous adipose. diagnosed via biopsy. More common on females, middle aged, posterior legs.

Erythema Nodosum - young woman, anterior
Erythema Induratum - older, posterior