Multicentric reticulohistiocytosis

Abstract

Multicentric reticulohistiocytosis (MRH) is a rare systemic disease characterized by the combination of typical papular and nodular skin lesions and a severe and destructive polyarthritis, although virtually any organ system of the body can be involved. MRH most commonly affects middle-aged white women; it is about three times more common in women with a mean age at onset in the fifth decade. MRH is a rare histiocytic proliferative disease of unknown aetiology, characterized by tissue infiltration by histiocytes and multinuclear giant cells. The stimulus for the histiocytic proliferation has not been fully elucidated, although there is an association with internal malignancies and abnormal immunological laboratory findings. The diagnosis is confirmed by skin or synovial biopsy. The disease often runs a waxing and waning course and sometimes stabilizes. Work-up for underlying malignancy cannot be overemphasized. The recommended treatment for MRH is oral methrotrexate plus prednisone tapered gradually over 3–4 months.