Oral acyclovir for the prevention of herpes-associated erythema multiforme.

Herpes simplex virus is the single most common precipitator of erythema multiforme. Typically, erythema multiforme lesions appear 10 to 14 days after a recurrent herpes simplex virus infection and attacks can be disabling when they occur at frequent intervals. Prior to the introduction of acyclovir (Zovirax), there was no effective therapy to prevent herpes-associated erythema multiforme. Four patients were treated with a maintenance dose of acyclovir for periods ranging from 10 to 26 months; there were no significant side effects from the drug and only one recurrence of erythema multiforme. Oral acyclovir may become the treatment of choice for herpes-associated erythema multiforme.