Fibroblastic rheumatism (FR) is a rare fibroproliferative disease with an unknown etiology. The absence of typical symptoms makes early diagnosis challenging. This study aims to systematically review FR cases and present a case from our center to provide a comprehensive description of the clinical manifestations, diagnosis, and treatment, thereby assisting clinicians in early identification and timely management of FR, ultimately leading to improved prognosis.

FR is a rare fibroproliferative disease with an unknown etiology. It is characterized by rapidly progressive and destructive symmetrical inflammatory multiple arthritis. Here, we present a rare case of a 50-year-old female with symmetric inflammatory polyarthritis. We highlight the importance of a comprehensive medical history, histopathology, immunohistochemistry, and clinical manifestations of skin nodules, arthralgia, and arthritis for successful disease diagnosis. Despite employing non-steroidal anti-inflammatory drugs, corticosteroids, methotrexate, and tacrolimus, the patient's symptoms did not resolve, and joint destruction continued to progress. Early diagnosis, aggressive treatment with appropriate use of steroids and immunosuppressants, and further research to identify effective treatment strategies are crucial in preventing detrimental joint destruction and limb contractures.

A comprehensive review of the available literature emphasizes the importance of early and accurate diagnosis coupled with appropriate treatment for achieving favorable outcomes and preventing joint destruction and limb contractures.

Fibroblastic rheumatism (FR) is an uncommon disease of the skin, characterized by the presence of non-tender cutaneous nodules accompanied often by other rheumatic manifestations. This condition shows male predominance, no age preference and unpredictable course, resulting frequently in permanent joint damage. A 60-year-old man came to our department with a 4-year history of multiple non-tender nodules and morning stiffness affecting mainly the upper extremities. Clinical examination revealed arthritis of the hands, confirmed by imaging tests. Laboratory exams were unremarkable. A skin nodule biopsy showed a dermal collagenous lesion with myxoid areas composed of spindle and stellate cells. Immunohistochemical staining demonstrated positivity for CD68 and negativity for CD34, S100, EMA and desmine. FR was diagnosed and the patient started methylprednisolone 16 mg/day. Hydroxychloroquine 400 mg/day and methotrexate 15 mg/weekly were further added as steroid-sparing agents with clinical benefit. Clinicians should be aware of this underreported entity, which can rapidly lead to irreversible deformities.

Fibroblastic rheumatism is a very rare cause of distal and bilateral polyarthritis characterized by cutaneous nodules, sclerodactylitis, thickened palmar fascia and Raynaud phenomenon. Physiopathology remains unknown and the diagnosis is histologic. Despite the use of immunosuppressive agents in some isolated cases with a variable efficacy, we report a case of typical fibroblastic rheumatism with severe digital retraction who dramatically improved after intensive physical therapy without immunosuppressive drugs prescription. Such a case illustrates that improvement may be spontaneous and that non pharmacological approach is a cornerstone in the management of this disease.

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.