Janus kinase inhibitor for multicentric reticulohistiocytosis, a new potential treatment.

Multicentric reticulohistiocytosis (MRH) is a rare systemic disorder characterized by inflammatory histiocytic infiltrates, mainly affecting the synovium, skin, and subcutaneous tissues. More patients are needed to confirm the effectiveness of JAKi treatment; but we suggest JAKi as a promising treatment option for MRH, especially when conventional drugs have failed. Additionally, CD1a and S100 stains are negative, indicating that the histiocytes are not Langerhans cells.[2] As the etiology and pathogenesis of MRH remain unknown, treatment of MRH remains largely empirical. It is more commonly observed in women (female:male ratio of 3:1) with mean presentation age between 40 and 50 years old.[2] Arthropathy is often rapidly progressive and can lead to destructive arthritis in 50% of MRH cases and flexion deformities in 14%.[[2]] Distal interphalangeal joints are the most frequently involved, and are one of the defining characteristics of MRH. [Extracted from the article]