Erythema Multiforme

Question 1

EM

Answer 1

acute, self limiting widespread eruption, often a/w immediate preceding infection

Question 2

2 categories of EM

Answer 2

EM minor: no mucosal involvement. EM major: mucosal involvement and systemic symptoms such as fever and arthralgias

Question 3

3 subacute types of EM

Answer 3

Isolated, Recurrent (most common, 1-2 flares per year) Persistent

Question 4

Epidemiology

Answer 4

< 1%, young adults, no racial preponderance, 90% a/w infection like HSV1/HSV2, Epstein Barr, pneumonia

Question 5

medications related to EM

Answer 5

NSAIDs, abx, sulfa, seizure meds

Question 6

pathogenesis

Answer 6

may be a genetic predisposition, HSV related is most common, drug related may be due to toxic metabolities from abnormal breakdown

Question 7

Clinical features

Answer 7

young adults, rash preceded by fever, malaise, myalgia,

Question 8

Classic lesion

Answer 8

3cm or less, shape of a target, erythema and edema is prominent, central can be purple or blue, spreads during course of illness and coalesces

Question 9

time from onset to resolution

Answer 9

< 4 weeks. lesions resolve in 1-2 weeks. if oral involvement may last 6 months

Question 10

2 zones of lesion

Answer 10

outer with erythema and induration, inner with epidermal damage of necrosis and blisters. heals without scarring. starts extremities and progress centrally

Question 11

ddx

Answer 11

SJS, TEN, Fixed drug eruption, polymorphus light eruption, cutaneous lupus, PR, urticaria

Question 12

diagnostic criteria

Answer 12

no specific labs, in more severe: ESR and liver enzymes elecated, ANA negative.

Question 13

hsv testing

Answer 13

if suspected, culture, PCR

Question 14

if resp symptoms rule out

Answer 14

mycoplasma pneumonia – CXR, PCP throat swab, serology for m pneumoniae

Question 15

tx

Answer 15

identify precipitating infection r medication

Question 16

if extensive mucosal involvement

Answer 16

fluid and electrolyte balance in the hospital, monitor infection, prevent sepsis

Question 17

opthamology involvement

Answer 17

reduce complications of conjunctivitis, uveitis, corneal scarring

Question 18

EM minor, pharm mgmt

Answer 18

symptomatic, oral antihistamines for burning or swelling, topical steroids

Question 19

EM major, pharm mgmt

Answer 19

40-80mg oral steroid daily until clear with a 1 week taper

Question 20

Oral involvement pharm mgmt

Answer 20

oral topical steroid gel, antiseptic anesthetic mouth rinse

Question 21

if recurrent HSV

Answer 21

Acyclovir 400mg BID

Question 22

If resistent

Answer 22

dapsone, hydroxychloroquine

Question 23

will anivirals help with an acute outbreak?

Answer 23

no

Question 24

for recurrent persistent unresponsive EM work up for

Answer 24

autoimmune disease, malignancy, infectious process

Question 25

distrubtion of rash

Answer 25

extremities is more dx of EM, trunk and face is more dx of SJS