Clinical Features and Pathogenesis of Chronic Bullous Disease of Childhood

Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin. It is associated with an autoantibody response directed against BP180 (BPAG2) and BP230 (BPAG1-e), two components of junctional adhesion complexes in the skin called hemidesmosomes. BP, which typically occurs in the elderly, has a broad spectrum of clinical features and often represents a diagnostic challenge. BP typically presents with a highly pruritic generalized blistering eruption associated with eczematous and/or urticarial infiltrated lesions, with vesicles and blisters. Nevertheless, in up to 20 % of cases, blisters and postbullous erosions may lack. In these cases, the disease closely mimics a variety of other inflammatory dermatoses, such as contact dermatitis, toxic drug reaction, ectoparasitosis, fixed urticaria, and chronic prurigo, or simply leads to chronic secondary scratch lesions. Therefore, it is time to rename bullous pemphigoid as cutaneous pemphigoid, a term with broader catchment in the spectrum of clinical presentations and with the implication that the involvement of mucous membrane sites is not predominant. In all cases, the diagnosis of BP critically relies on direct immunofluorescence microscopy studies to demonstrate tissue-bound C3 and/or IgG immune deposits along the cutaneous basement membrane zone.