Multicentric reticulohistiocytosis presenting with a rash and arthralgia.

A case of multicentric reticulohistiocytosis in a 53-year-old woman with a history of generalized cutaneous eruptions followed by arthralgia is presented. A thorough malignancy screen was performed with negative results. Treatment was commenced with oral prednisone 20 mg daily, which rapidly resulted in marked improvement of joint symptoms and resolution of self-perceived functional disability. As there was little improvement of her rash, oral azathioprine was added at 100 mg daily. Both drugs were well-tolerated and the patient was discharged from hospital on these medications. Two months later the azathioprine was reduced to 50 mg per day orally, following a small rise in hepatic transaminases. Within 4 months there had been dramatic improvement in the rash and cutaneous nodules with complete remission of the arthralgia and pruritus. During this time the oral prednisone had gradually been decreased to 10 mg daily. To date only the periungual nodules persist.