Lesions induced by trauma in pemphigoid.

Three patients are described with pemphigoid (two with typical adult type and one with juvenile pemphigoid) in whom bullous lesions had clearly been induced by the trauma of scratching. In two patients this phenomenon occurred during the first few weeks of systemic corticosteroid treatment at a time when other lesions were resolving or had completely healed. Although lesions induced by trauma are not usually of great clinical importance, epidermolysis bullosa acquisita may represent a variant of pemphigoid in which trauma-induced lesions predominate. Induction of pemphigoid lesions by trauma may prove a useful method of studying early immunopathological events.