A subepidermal bullous eruption associated with IgG autoantibodies to a 200 kd dermal antigen: The first case report from the United States

We describe an 81-year-old white man in whom a subepidermal bullous eruptio n developed that clinically resembled bullous pemphigoid. The eruption prom ptly responded to oral tetracycline and niacinamide and topical clobetasol. Histologic examination of perilesional skin revealed neutrophilic infiltra tion with formation of papillary microabscesses and subepidermal cleavage. Direct immunofluorescence showed linear deposition of IgG and C3 along the basement membrane zone. By indirect immunofluorescence, circulating IgG aut oantibodies bound exclusively to the dermal side of salt-split normal human skin. Immunoblot analysis demonstrated that the patient's autoantibodies r eacted with a 200 kd dermal protein that was different from type VII collag en, the epidermolysis bullosa acquisita autoantigen. This patient represent s the first confirmed case from the United States with a recently reported novel autoimmune subepidermal bullous disease associated with IgG autoantib odies to a 200 kd dermal antigen.