Dapsone in the treatment of persistent erythema multiforme.

Erythema multiforme (EM) is usually an acute and self-limited inflammatory reaction of the skin and mucous membranes. Attacks may be sporadic or recurrent, and generally last for 1 to 3 weeks. Rarely, an episode of EM may fail to abate. This continuous and uninterrupted occurrence of typical and atypical lesions is known as persistent EM. We present a case responsive to dapsone.