Viru-Merz® ointment,1% tromantadine hydrochloride, is a topical antiviral agent used for recurrent herpes simplex. There are many reported cases of contact dermatitis by tromantadine.But erythema multiforme-like eruptions in association with Viru-Merz® Ointment has not been reported. A 31-year-old woman, who applied Viru-Merz® ointment for a recurrent herpes simplex labialis, developed an allergic contact dermatitis. Erythema multiforme like eruptions with typical target feature followed around the eczematous lesions on the face, and spread progressively on the neck and trunk. A patch test revealed positive reaction to Viru-Merz® ointment.