Stevens-Johnson syndrome and toxic epidermal necrolysis from pathologist's point of view.

Stevens-Johnson syndrome and toxic epidermal necrolysis (Lyell syndrome) are rare diseases characterized by rapid blistering followed by extensive skin and mucosal exfoliation and constitutional symptoms. In most cases, drugs are the main triggers, but the etiopathogenesis of the diseases is not fully understood. Lyell syndrome is associated with a high mortality rate, reported to be around 35%. Therefore, early diagnosis requiring close interdisciplinary cooperation is essential. The diagnosis based on the clinical picture and a detailed pharmacological history should be confirmed by histopathological examination of the skin specimen, including analysis by direct immunofluorescence.