Erythema multiforme

Erythema multiforme is a hypersensitivity reaction that is most commonly triggered by infections. It may be divided into minor and major forms.

Previously it was thought that Stevens-Johnson syndrome (SJS) was a severe form of erythema multiforme. They are now however considered as separate entities.

Features

• target lesions
• initially seen on the back of the hands / feet before spreading to the torso
• upper limbs are more commonly affected than the lower limbs
• pruritus is occasionally seen and is usually mild

Causes

• viruses: herpes simplex virus (the most common cause), Orf ^
  • (^ Orf is a skin disease of sheep and goats caused by a parapox virus**)**
• idiopathic
• bacteria: Mycoplasma, Streptococcus
• drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
• connective tissue disease e.g. Systemic lupus erythematosus
• sarcoidosis
• malignancy

Erythema multiforme

Erythema multiforme

Erythema multiforme