Erythema Multiforme

Key Features

• Erythema multiforme has sometimes been diagnosed in patients with severe mucous membrane involvement, but Stevens-Johnson syndrome is the diagnosis when severe involvement of conjunctiva, oral cavity, and genital mucosa also occur

• Many causes are suspected, particularly concomitant herpes simplex virus (HSV); drugs, especially sulfonamides; and Mycoplasma infections

• Recurrent erythema multiforme is usually associated with reactivation of HSV

• In erythema multiforme, spontaneous healing occurs in 10–14 days, but Stevens-Johnson syndrome may last 6–8 weeks

Clinical Findings

• Papules that later develop a dark center

• Lesions with central bluish discoloration or blisters

• Characteristic target lesions (iris lesions) that have three concentric circles of color change

Diagnosis

• Clinical

Treatment

• Treatment is symptomatic in uncomplicated erythema multiforme

• Discontinue offending drugs

• Oral antihistamines such as cetirizine 5–10 mg every morning and hydroxyzine 1 mg/kg/d at bedtime are useful

• Cool compresses and wet dressings relieve pruritus

• Corticosteroids have not been demonstrated to be effective

• Long-term acyclovir therapy has been successful in decreasing attacks in patients with HSV-associated recurrent erythema multiforme