Pemphigoid nodularis (non-bullous): a clinicopathological study of five cases.

Pemphigoid nodularis is a rare clinical variant of pemphigoid characterized by overlapping clinical features of both prurigo nodularis lesions and pemphigoid-like blisters. In pemphigoid nodularis, the immunopathological findings are identical to those of bullous pemphigoid (BP). We describe five patients who presented with the typical clinical phenotype of prurigo nodularis, who were found to have circulating and tissue-bound antibasement membrane zone autoantibodies. By immunoelectron microscopy and Western immunoblotting studies, the circulating antibodies were shown to target the hemidesmosome and specifically the BP antigens 1 and 2 (BP180 and BP230). In contrast to the majority of reported cases, none of these patients has ever developed blisters. The role of antibasement membrane zone antibodies in the development of the eruption, or the role of the eruption in the development and persistence of autoantibodies, is not clear. These cases demonstrate that the presence of these antibodies is not sufficient for the development of blisters.