Erythema multiforme

Abstract

Although erythema multiforme (EM) is usually considered a single disease, a useful way of looking at it has been emphasized by Tonnenson and Huff, 1 who separate major and minor types. EM minor is milder, and may have mucosal involvement, but usually is without constitutional symptoms. EM major is life-threatening, bullous, and has extensive mucosal involvement and severe constitutional symptoms (Stevens-Johnson syndrome). Both forms may exhibit the distinctive target lesions. Drug-induced toxic epidermal necrolysis (TEN) is the most severe form of the disease. Drug-induced EM is a hypersensitivity reaction to a drug-related antigen. Other inciting agents are herpes simplex virus and Mycoplasma pneumonia infections.