Fibroblastic rheumatism: an uncommon arthritis. A case-based review.

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.