Multicentric reticulohistiocytosis (MRH) is a rare non-Langerhans histiocytosis of unknown etiology characterized by papulonodular skin lesions and progressive, erosive arthritis. To date, there have been approximately 300 cases of MRH reported worldwide. The majority of patients are Caucasian from western countries, and Asian patients are rare. Here, we report a case of MRH in a Chinese patient.

A 38-year-old male was admitted to the hospital with a rash that had persisted for over 2 years and bilateral knee pain for over 1 year. The patient’s symptoms had previously been misdiagnosed as eczema when there were only skin symptoms and was finally diagnosed as MRH after a skin biopsy of the left upper back. The patient was treated with glucocorticoids combined with an immunosuppressive regimen. While the skin lesions on both arms, abdomen, and back subsided, the skin lesions on the rest of the body did not increase. The interphalangeal joints of both thumbs and bilateral knee joints remained swollen and painful.

The case will help clinicians better identify and treat this disease in the absence of epidemiological studies or randomized controlled data.

• Multicentric reticulohistiocytosis
• Papulonodular skin lesions
• Arthritis
• CD68
• Case report

Multicentric reticulohistiocytosis is a rare disease affecting skin and joints primarily and rarely other organs. We present a case report of this disease and an extensive review of the literature. We reviewed the data between 1991 and 2014 and extracted 52 individual cases. Only articles in English were chosen after checking for relevance. The articles were studies and data was extracted into excel spread sheets and later used to compute such variables like frequency, mean and percentage of distribution of various clinical manifestations. The treatments used in these articles were critically analyzed and graded for their relative efficacy for skin and joint manifestations. The grades were 0 = worse, 1 = no benefit/condition remained same, 2 = improvement without resolution, and 3 = resolution. This article also reports the demographic, clinical, laboratory and pathological data from the reviewed articles. Authors attempted to discuss the findings of this review in depth to help manage this condition and proposed a treatment algorithm to help clinicians approach this rare and challenging disease.

• Arthritis
• Autoimmune disease
• Immunosuppressive medications
• Skin disease

• Adult
• Diagnosis, Differential
• Female
• Histiocytosis, Non-Langerhans-Cell/diagnosis
• Histiocytosis, Non-Langerhans-Cell/drug therapy
• Histiocytosis, Non-Langerhans-Cell/pathology
• Humans
• Immunosuppressive Agents/therapeutic use
• Methotrexate/therapeutic use
• Skin Diseases/diagnosis
• Skin Diseases/drug therapy
• Skin Diseases/pathology

• Adult
• Antigens, CD/analysis
• Antigens, Differentiation, Myelomonocytic/analysis
• Biopsy
• Bone Marrow/pathology
• Cytoplasm/pathology
• Female
• Histiocytes/pathology
• Histiocytosis, Non-Langerhans-Cell/diagnosis
• Histiocytosis, Non-Langerhans-Cell/pathology
• Humans
• Immunohistochemistry
• Immunophenotyping
• Microscopy, Electron
• Muscles/pathology
• Periodic Acid-Schiff Reaction
• Skin/pathology