Erythema Multiforme

Question 1

What kind of immune reaction is responsible in Erythema multiforme?

Answer 1

Delayed Type IV hypersensitivity reaction to drugs/infection

Question 2

What infections/Conditions can cause Erythema multiforme?

Answer 2

HSV-1 or HSV-2
Mycoplasma
Fungal

Lupus
Hepatitis
Lymphoma

Question 3

What drugs can trigger Erythema Multiforme?

Answer 3

• Barbiturates
• NSAIDs
• PCN
• Sulfonamides
• Allopurinol
• Phenytoin, Phenothiazines, Hydantoins

Question 4

How much body surface area is involved with Erythema Multiforme?

Answer 4

<10%

Question 5

How do you treat erythema multiforme?

Answer 5

discontinue the drug

MIld = no tx
- Will resolve spontaneously in 3-5wks

Recurrent
- Acyclovir

Question 6

EM major

Answer 6

One or more mucous MBs involved

- oral, genital, ocular

Question 7

Is EM systematically distributed?

Answer 7

Yes

Question 8

Describe the rash of EM

Answer 8

Polymorphous eruption - macules—>papules—> target lesions —-> vesicles/bullae

Sharply demarcated/crusting/blistering of center

Question 9

Describe the target lesion of EM

Answer 9

3 concentric zones

Central dark papule
Pale area
Halo of erythema

Question 10

What’s the prodrome of EM?

Answer 10

Fever, malaise

Question 11

Where can the EM rash be found?

Answer 11

Oral mucosa, palms & soles, generalized

Question 12

What is the most common cause of EM?

Answer 12

Herpes simplex virus

Question 13

Does EM have a negative or positive Nikolsky sign?

Answer 13

Negative Nikolsky sign

Question 14

What are other causes?

Answer 14

Malignancy
Autoimmune status
Idiopathic

Question 15

Common drugs that cause EM

Answer 15

S - sulfa
O - oral hypoglycemics 
A - Anticonvulsants
P - PCN
S - NSAIDS

Question 16

EM minor

Answer 16

Minimal or no mucous MB involved

Localized skin eruption