Erythema multiforme.

Erythema multiforme is a skin condition considered to be a hypersensitivity reaction to infections or drugs. It consists of a polymorphous eruption of macules, papules, and characteristic "target" lesions that are symmetrically distributed with a propensity for the distal extremities. There is minimal mucosal involvement. Management involves treating the existing infectious agent or discontinuing the causal drug. Mild cases resolve without sequelae and do not require treatment. Recurrent cases have been prevented with continuous acyclovir. Patients who have no response to acyclovir may have a response to valacyclovir or famcilovir, which have greater oral bioavailability and more convenient dosing. Patients with recurrent erythema multiforme despite suppressive antiviral therapy should be referred to a dermatologist for further treatment.