Erythrodermic bullous pemphigoid
Authors: Amato Lauretta , Gallerani Isabella , Mei Sandra , Pestelli Elisabetta , Caproni Marzia , Fabbri Paolo 
Published: March 2003

Case 1 An 87‐year‐old man, with a 2‐year history of a generalized exfoliative erythroderma involving approximately 90% of the body, presented with an onset of tense blisters symmetrically distributed on most of his body.Clinical examination revealed generalized erythema, edema, moderate lichenification, and scaling, with several tense and grouped blisters on the hypocondrium, buttocks, left knee, and back of the left hand (Fig. 1). A biopsy specimen, taken from lesional erythematous skin, revealed a dermal–epidermal separation with a mixed inflammatory infiltrate containing numerous eosinophils. Direct immunofluorescence of perilesional skin on the abdomen demonstrated linear deposition of immunoglobulin G (IgG) and C3 at the basement membrane zone (BMZ) (Fig. 2). Indirect immunofluorescence demonstrated serum IgG antibodies directed against BMZ antigens at a titer of 1 : 20. Utilizing salt‐split human skin as a substrate, serum revealed the presence of IgG antibodies that bound to the epidermal side at a titer of 1 : 80. Blotting studies demonstrated circulating IgG antibodies which bound to the 180 kDa bullous pemphigoid (BP) antigen (Fig. 3). Human leukocyte antigen (HLA) typing revealed A3, B41, Cw2, DR4, DR11, DRw53, and DQ3.Several small, tense, grouped blisters associated with diffuse erythema and moderate lichenification and scaling localized on the anterior surface of the trunkimageLinear deposition of immunoglobulin G and C3 at the epidermal basement membrane zone (direct immunofluorescence)imageCirculating immunoglobulin G antibodies against the 180 kDa bullous pemphigoid antigen (immunoblotting)imageWithin 3 weeks of treatment with oral prednisone, 50 mg, complete clinical resolution occurred. Case 2 An 85‐year‐old man presented with a 3‐month history of bullous lesions. These lesions developed on infiltrated erythematous–edematous skin. Two months after the onset of blisters, he developed an erythroderma involving all of the body except for the face and groin.Physical examination revealed erythroderma associated with disseminated large erosive areas and tense blisters of variable sizes localized on the knees and on the flexural surfaces of the legs (Fig. 4).Erosive areas of variable sizes localized on the flexural surfaces of the legsimageHistopathologic examination of a lesional skin biopsy showed a dermal–epidermal separation with an eosinophilic and neutrophilic infiltrate in the superficial dermis.Direct immunofluorescence demonstrated a linear deposition of IgG and C3 at the epidermal BMZ. Indirect immunofluorescence demonstrated serum IgG antibodies directed against BMZ at a low titer (1 : 20). Utilizing salt‐split human skin as a substrate, serum IgG autoantibodies that bound to the epidermal side at a titer of 1 : 40 were demonstrated. The analysis of HLA antigens demonstrated the following haplotypes: A2, A3, B49, B62, C3, C7, DR4, DR8, DRw53, and DQ8.Within 4 weeks of treatment with prednisone, 50 mg daily, there was complete resolution of the blisters and of the erythroderma