Lichen planus and bullous pemphigoid.

A patient is described who had clinical and histopathological features of lichen planus and bullous pemphigoid; deposits of in vivo bound C3 at the basement membrane zone, which, at the electron microscopy level, were deposited in the lamina lucida; and with circulating IgG antibasement membrane zone antibodies which exhibited a pronounced C3 binding capacity. The similarity of our case to others described in the literature suggests that bullous lichen planus in fact represents the coexistence of two distinct diseases, namely lichen planus and bullous pemphigoid.