Kumiko Honoki

Linear IgA bullous dermatosis with circulating IgG autoantibodies to the 230 kD epidermal antigen.

The patient was a 54‐year‐old woman with wide‐spread bullous lesions on her trunk and oral mucosa. Histologic examination revealed a subepidermal blister with infiltration of neutrophils and eosinophils. Direct immunofluorescence showed an exclusively IgA deposition at the basement membrane zone (BMZ). Indirect immunofluorescence showed that the blister fluid, but not the serum, contained IgG antibodies against the BMZ antigen on the epidermal side of salt‐split skin. Using immunoblot analysis with normal human epidermal extracts, both serum and blister fluid reacted with the 230 kD epidermal antigen. Using colloidal gold and direct immunoelectron microscopy, IgA deposition was detected in the lamina lucida. Clinically, the skin lesions responded well to dapsone.

A Case of Nonscarring Inflammatory Epidermolysis Bullosa Acquisita: Characterization of IgG Autoantibodies by Immunofluorescence, Immunoblotting and Immunogold Electron Microscopy

We report a case of nonscarring inflammatory epidermolysis bullosa acquisita in a 59‐year‐old Japanese woman. She developed blisters and erosions on her lip, trunk and extremities. Sodium aurothiomalate was effective for the skin lesions. The patient had been free from bullous skin lesions for the last 13 years and had shown no scarring. Indirect immunofluorescence (IF) study on 1 M NaCl‐split skin revealed IgG autoantibodies against the dermal side of the split skin. Immunoblotting using normal human dermal extracts disclosed IgG autoantibodies reactive with the 290 and 145 kD antigens. Circulating IgG autoantibodies were deposited on the lamina densa by immunoelectron microscopy. IF mapping using several antibodies for the components of the basement membrane zone revealed blister formation at the lamina densa. These results suggest that the cleavage at the lamina lucida does not necessarily exclude the diagnosis of EBA and that the definite diagnosis of EBA should be confirmed by immunoblotting or immunoelectron microscopic study.

INTRAEPIDERMAL EXPRESSION OF BASEMENT MEMBRANE COMPONENTS IN THE LESIONAL SKIN OF A PATIENT WITH DYSTROPHIC EPIDERMOLYSIS BULLOSA

The patient was a 15‐year‐old male. Since birth, he had developed blistering and erosion of the skin. Biopsy skin specimen of the bullous lesions showed subepidermal blister formation. Electron microscopic examination revealed that tissue separation had occurred at the sublamina densa level. By indirect immunofluorescence using antibodies specific for α6 integrin, laminin 5, type IV collagen, and type VII collagen, all of these basement membrane components were detected as coarse granular intracytoplasmic deposits only in the basal and suprabasal cells of the blister roof. In the non‐blistered regions, these basement membrane components showed a linear pattern similar to that seen in normal skin. These findings suggest that intraepidermal expression of basement membrane components was closely related to the blister formation. The biological meaning of intraepidermal expression of basement membrane components were also discussed.

Localized Cutaneous Amyloidosis Simulating Lichen Simplex Chronicus

We report a case of localized cutaneous amyloidosis in a 42‐year‐old Japanese woman. Skin lesions were confined to the nuchal area, and the clinical appearance resembled that of lichen simplex chronicus. Our experience with this case indicates that, in cases presenting with persistent skin lesions simulating lichen simplex chronicus, amyloid should be specifically looked for in biopsy material.