Coexistence of lichen planus and bullous pemphigoid. A immunopathological study.

A 43-year-old white man presented with a generalized eruption of lichen planus and tense blisters within the lichenoid lesions and also on clinically normal skin. Direct immunofluorescence (IF) studies revealed immunological and histopathological characteristics of lichen planus in the lichenoid lesions and of bullous pemphigoid in the bullous lesions, and indirect IF studies showed that the patient had circulating antibasement membrane antibodies. The coexistence of both disorders may indicate a possible link between the pathology in the junctional zone in lichen planus and the appearance of antibasement membrane zone antibodies and bullous lesions, respectively.