Erythema multiforme

Question 1

What is the difference between erythema multiforme minor and erythema multiforme major?

Answer 1

EM minor - only cutaneous involvement

EM major - at least one mucosal surface involvement (more severe)

Question 2

Erythema multiforme is usually self limiting. T/F?

Answer 2

True

Question 3

What are the potential infectious causes of erythema multiforme?

Answer 3

HSV
VSV
EBV
Cytomegalovirus
Mycoplasma pneumoniae
Hepatitis B
Histoplasmosis

Question 4

What are the potential drug causes of erythema multiforme?

Answer 4

Anticonvulsants
Penicillins
Antimalarials
OCP
Lidocarine
TNF-alpha inhibitors

Question 5

How many days post-exposure to a causative agent does erythema multiforme usually present?

Answer 5

4-7 days

Question 6

Which skin condition characteristically causes haemorrhagic crusting of the vermiform region of the lips?

Answer 6

Erythema multiforme major

Question 7

Describe the rash appears of erythema multiforme?

Answer 7

Erythema
Macules
Papules
Vesicles
Bullae
Characteristic annular target lesions with central necrosis
Rash is only itchy once the lesions start to heal

Question 8

Erythema multiforme is a clinical diagnosis, but how can diagnosis be confirm if needed?

Answer 8

Skin biopsy

Question 9

What is the management of erythema multiforme (both minor and major forms)

Answer 9

Sterile wound care
Topical emollients
Corticosteroids (topical, oral or IV, as appropriate)
Analgesia
Treatment of underlying infection / removal of causative drug

Question 10

What management strategies are used in the treatment of erythema multiforme major but not EM minor?

Answer 10

Lidocaine and mouthwash for oral ulcers
IV fluid (if fluid deplete) 
Catheterisation

Question 11

What are the potential complications of erythema multiforme?

Answer 11

Secondary bacterial infection

Scarring