Erythema multiforme

**Definition:** Erythema multiforme is a self‐limiting reactive inflammatory dermatosis triggered by cell‐mediated hypersensitivity, most commonly to drugs or infection, particularly Herpes simplex. It is characterised by an eruption of macules, papules, nodules, vesicles and/or bullae affecting preferentially the dorsal aspects of the hands and forearms. It may also involve oral and genital mucous membranes.

**Exclusions:** - Stevens-Johnson syndrome or toxic epidermal necrolysis