Allopurinol is widely used for chronic tophaceous gout as a uric acid lowering agent. Hyperse- nsitivity to allopurinol occurrs in about 10% of patients, which limits the usage of allopurinol. The successful oral and intravenous desensitization of allopurinol has been reported worldwide since 1976. We recently experienced a 51-year-old male patient with gouty arthritis and hyperuricemia, who had previously experienced skin rash after allopurinol treatment. When allopurinol was re- tried, erythematous and foliative skin rash developed on entire body. Because allopurinol was es- sential in controlling hyperuricemia, the oral desensitization of allopurinol was tried. We report successful rapid oral allopurinol desensitization in the patient with chronic tophace- ous gout, who exhibited exfoliative dermatitis as allopurinol hypersensitivity.