A 3-year-old boy presented with a generalized bullous disease, clinically strongly indicative of chronic bullous disease of childhood (CBDC). The diagnosis was confirmed by histopathology and further verified by several immunological and biochemical examinations. Direct immunofluorescence (IF) of perilesional skin revealed in vivo bound IgA-autoantibodies (aabs) in a linear pattern along the basement membrane zone; indirect IF revealed circulating IgA-aabs bound to the roof of "split skin" preparations of healthy human skin; immunoblotting of epidermal protein extracts showed that the aabs bound to a 97KD/120KD protein. Therapy with 4,4'-diaminodiphenylsulfone (DADPS, 2 mg/kg /daily), combined with prednisolone for the first month, was initiated, and promptly led to complete remission. Two attempts to stop DADPS treatment after 3 and 5 years of continuous therapy were followed by prompt recurrences. The boy is now 8 years old; with continuous DADPS therapy (1 mg/kg body weight/d), he displays regular physical and intellectual development.