Epidermolysis bullosa acquisita in a 6‐year‐old Japanese boy

A 6‐year‐old Japanese boy started to develop blisters around the mouth and eyes in May 1996. With provisional diagnoses of herpes simplex or Kaposi's varicelliform eruption, he was treated with acyclovir and immune globulin. Blister formation increased, however, and he was referred to the Dermatology Clinic of Kobe University School of Medicine in August 1996. On physical examination, tense bullae and vesicles were observed on the trunk and limbs and also on the palms and soles ( Fig. 1 ). Neither mucosal involvement nor cutaneous fragility was observed, and no nail deformity was seen. The blistering on both erythematous bases and normal skin showed a “string‐of‐pearls” arrangement. Abnormal laboratory results were as follows: white blood cell count, 12.4×10 3 /mm 3 (N = 4–8.5) (eosinophils, 25%); platelets, 514×10 3 /mm 3 (N = 130–300); total protein, 4.9 g/dL (N = 6.5–7.8); albumin, 2.4 g/dL (N = 4.1–5.0); glutamate pyruvate transaminase (GPT), 56 IU/L (N = 7–34); lactate dehydrogenase (LDH), 573 IU/L (N = 227–416); alkaline phosphatase (ALP), 384 IU/L (N = 100–303); C‐reactive protein (CRP), 3.08 mg/dL (N = 0–0.3). The antinuclear antibody test gave negative results. Disseminated tense blisters with an annular pattern developing on erythematous plaques on the trunk image Histologic examination of a skin biopsy specimen revealed a subepidermal blister containing neutrophils and eosinophils, and an infiltrate of lymphocytes with eosinophils and neutrophils in the superficial dermis. Direct immunofluorescence of perilesional skin showed a linear band of immunoglobulin G (IgG) and C3 at the dermo–epidermal junction. Indirect immunofluorescence on 1 mol/L sodium chloride‐split normal skin showed IgG deposits on the dermal side of the blister. Western immunoblot analysis of the reactivity of the patient's serum on epidermal and dermal extracts revealed that autoantibodies were bound to the 290‐kDa antigen in the dermal extract ( Fig. 2 ). No reactivity was observed in the epidermal extract. Western immunoblot analysis on a dermal extract. Lanes 1 and 2, adult EBA serum sample; lane 3, patient's serum; lane 4, normal control serum image The boy was treated with prednisolone (1.3 mg/kg body weight per day) which inhibited new blistering. Since a reduction of the dose of prednisolone to 1.1 mg/kg body weight per day induced new blistering,dapsone (1.6 mg/kg body weight per day) and prednisolone (1.1 mg/kg body weight per day) were given in combination, leading to improvement. A further decrease in the dose of prednisolone to 0.9 mg/kg body weight per day resulted in new bulla formation, and the prednisolone was replaced by betamethasone. The disease activity then markedly subsided and the bullae healed with the formation of milia.