Jaccoud's arthropathy, an unusual manifestation of idiopathic retroperitoneal fibrosis: rapid improvement of symptoms after tocilizumab treatment.

Jaccoud's arthropathy (JA) is a chronic, non erosive, rheumatoid-like deformity associated with rheumatic fever (RF) and systemic lupus erythematosus and with other diseases such as psoriatic arthritis, connective tissue diseases, hypocomplementemic urticarial vasculitis, infections, sarcoidosis and neoplasia. We described a case of JA in a patient with cutaneous psoriasis but with a particular disease evolution associated with idiopathic retropritoneal fibrosis (IRF), evaluated with computed tomography, magnetic resonance and 18F-FDG PET/ CT. The patient, following failure with steroids, methotrexate and etanercept, was treated with tocilizumab (8 mg/kg) once every 4 weeks for 6 months. A rapid improvement of symptoms and disappearance of 18F-FDG uptake was shown. We describe a review of literature of rheumatic manifestations of IRF and the possible role of interleukin-6 in the pathway of JA and IRF.