Successful Adjuvant Treatment of Recalcitrant Epidermolysis Bullosa Acquisita With Anti-CD20 Antibody Rituximab

A 46-year-old man of Turkish origin presented with a 4-month-history of blisters on both erythematous and apparently normal skin as well as erosions on oral mucous membranes. At a body weight of 75 kg, he had been treated with dapsone (150 mg/d) and prednisolone (initially 250 mg/d, then 100 mg/d), while new lesions continued to arise. After 1 month, dapsone was changed to azathioprine (100 mg/d). On physical examination, multiple blisters and extensive erosions on erythematous skin were seen on the entire integument, especially on the chest, abdomen, upper back area, and dorsal aspect of both hands (Figure1A). Scars and milia were found on the upper back area, and postinflammatory hyperpigmentation had developed at the sites of healed lesions. Also, erosions were present on the hard palate, the left buccal mucosa, and the gingiva of the upper and lower jaws. The nasal, genital, and perianal mucous membranes as well as the pharynx and larynx were unaffected. Upper gastrointestinal tract endoscopy and colonoscopy revealed no abnormalities. Histopathologic examination of a blister showed a subepidermal split and a dense inflammatory infiltrate in the upper dermis, dominated by lymphocytes and neutrophils. Direct immunofluorescence microscopy of a perilesional skin biopsy specimen revealed linear deposits of IgG, IgM, and C3 at the dermoepidermal junction (Figure 2A). Circulating IgG autoantibodies labeled the dermal side (bottom) of the artificial split on indirect immunofluorescence microscopy of 1M sodium chloride– split human skin at a titer of 1:80 (Figure 2B) and reacted with the recombinant noncollagenous domain 1 of type VII collagen on Western blotting (Figure 2C and D). No reactivity with the p200 protein (as seen in anti-