What is erythema multiforme?

➢ Erythema multiforme is characterized by epithelial injury mediated by skin-homing CD8+ cytotoxic T lymphocytes. ➢ It is an uncommon, usually self-limited disorder that appears to be a hypersensitivity response to certain infections and drugs. ➢ Antecedent infections include those caused by herpes simplex, mycoplasma, and some fungi ➢ Implicated drugs include sulfonamides, penicillin, salicylates, hydantoins, and anti-malarials. ➢ The cytotoxic T cell attack is focused on the basal cells of cutaneous and mucosal epithelia, presumably due to recognition of still unknown antigens.