Cimetidine and a delayed hypersensitivity reaction.

Oral cimetidine for the treatment of verruca continues to be a topic of discussion and controversy. Although its usage has gained popularity because it offers an alternative to conventional topical and surgical verruca therapy, its reported efficacy in managing warts lacks consistency in outcomes. Using high doses of oral cimetidine, therefore, raises concern about possible untoward effects. Cimetidine relies on effecting a change in the immune system to eradicate the verruca, but such a change in the immune system may cause patients to develop responses detrimental to their well being. The authors present an unusual case of severe delayed hypersensitivity with the use of oral cimetidine.