A case of anti-laminin γ1 pemphigoid with cutaneous polyarteritis nodosa

We report on a 40-year-old Japanese female who had anti-laminin γ1 pemphigoid with cutaneous polyarteritis nodosa. She noticed tense blisters on her bilateral palms and soles. Then she presented with disseminated edematous erythema that had small tense blisters arranged in an annular pattern over her entire body. Histological examination revealed subepidermal blisters and infiltration of neutrophils in the blisters, dermal-epidermal junction, and upper dermis. Direct immunofluorescence revealed linear deposits of IgG at the dermal-epidermal junction. However, deposits of immunoglobulins or complement in vessel walls were never shown. Indirect immunofluorescence using 1M NaCl split skin showed that IgG in the serum reacted exclusively with the dermal side of the split. However, the patient's IgG showed no reactivity with vessel walls of the capillaries in the dermis. Western blot analysis using dermal extracts showed that circulating IgG antibodies reacted to the 200-kD protein. Immunoblotting using recombinant protein of the C-terminus of laminin-γ1 showed the reactivity of circulating IgG antibodies. Oral administration of prednisolone, 40 mg per day, led to the gradual healing of erythemas and blisters. However, development of new blisters with erythema continued. Therefore, we added diamino diphenyl sulfone, 75 mg per day, and blister formation stopped completely. This was a rare disease, and it was very difficult to treat without getting a definitive diagnosis at the time of start of therapy.