Multicentric reticulohistiocytosis with pulmonary involvement

Multicentric reticulohistiocytosis with prominent skin lesions and arthritis: A case report

BACKGROUND

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.

CASE SUMMARY

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.

CONCLUSION

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

Organizing pneumonia associated with multicentric reticulohistiocytosis

Organizing pneumonia (OP) is a clinicopathological entity that occurs idiopathically or in association with several conditions such as connective tissue diseases. Multicentric reticulohistiocytosis (MRH) is a systemic disease characterized by polyarthritis and mucocutaneous lesions, but lung involvement is uncommon. We report a patient with MRH associated with OP. This case may be of interest when considering the pathophysiological mechanisms of both diseases.

Multicentric reticulohistiocytosis and fibroblastic rheumatism

Multicentric reticulohistiocytosis (MRH) and fibroblastic rheumatism (FR) are uncommon disorders with similar joint and skin manifestations. They are usually included among the non-Langerhans histiocytoses, but recent insights drive some criticism. The diagnosis is often challenging and must be confirmed by the histological typical features. If the skin manifestations are missing, the arthritic complaints may be confused with those of other rheumatic disorders. In these cases, only a careful clinical and radiological evaluation leads to the correct diagnosis. The natural course of the diseases may rapidly develop into disabling manifestations, making an aggressive treatment strongly recommendable. There is emerging evidence that anti-tumour necrosis factor-α agents and bisphosphonates are promising drugs for MRH, while a course of methotrexate and steroids seems to be the best option for FR. Finally, the clinician should be aware that in many cases MRH, but not FR, is associated with a large number of systemic manifestations and with malignancy. This eventuality must be accurately ruled out.

Skin disorders with arthritis

Many inflammatory, metabolic and infectious diseases affect the skin and joints. Most of these, such as rheumatoid arthritis and systemic lupus erythaematosus, are considered to be rheumatic conditions with secondary skin involvement. However, several primary cutaneous diseases are associated with arthritis and may even present with joint symptoms prior to cutaneous lesions. Common skin disorders, such as acne and psoriasis, have well-known musculoskeletal manifestations. Other less common conditions, such as dermatomyositis, multicentric reticulohistiocytosis, pyoderma gangrenosum, Sweet's syndrome and various cutaneous vasculitides, also have frequent joint involvement. This review will discuss the clinical presentation, both cutaneous and musculoskeletal, diagnosis and management of these disorders.