The authors present a case of acquired reactive perforating collagenosis developed in a nondiabetic hemodialysis patient, who was treated successfully with allopurinol. Treatment of acquired reactive perforating collagenosis is difficult and often ineffective. The patient had been unresponsive to conventional treatments, but the pruritus was controlled, and skin lesions subsequently resolved after the treatment with allopurinol. Possible mechanisms of allopurinol treatment for acquired reactive perforating collagenosis are discussed.