A Rare Case of Multicentric Reticulohistiocytosis

Multicentric reticulohistiocytosis (MRH) is a rare, histiocytic disorder that primarily affects the skin and joints. This disease can have systemic involvement of various organ systems and has been associated with underlying malignancy. Middle-aged, Caucasian females are the most commonly affected demographic group in this disease. We present a case of a 56-year-old African American male with debilitating joint pain and a papulonodular rash on his face, chest, arms, and hands. Biopsy of skin lesions confirmed the diagnosis of multicentric reticulohistiocytosis. Histological findings revealed dermal infiltrate composed of glassy histiocytes and giant cells with eosinophilic cytoplasm. The patient was started on 15 mg of methotrexate weekly, 1 mg of folic acid daily, and 60 mg of prednisone daily with mild improvement of skin lesions at one month followup. He expired from other comorbidities before long term treatment could be achieved. The potential for disfiguring skin lesions and debilitating arthropathy emphasizes the importance of early recognition and treatment of MRH. Corticosteroids and methotrexate are recommended for patients with moderate to severe disease and have been shown to be successful in some cases. More studies are needed on patients with MRH to further elucidate the etiology and pathogenesis of this disease.