Poncet’s disease: A challenging cause of polyarthritis in a Moroccan patient

Abstract Background Poncet’s disease is a reactive polyarthritis associated to active tuberculosis with excluded presence of mycobacterium in the joints and bones affected; it is an infrequent form of tuberculosis and challenging diagnosis condition with unknown pathogenesis. We report a case of Poncet’s disease in Moroccan patient to contribute data which could result in a consensus of clinical criteria. Case report A 38-year-old female was admitted to the Rheumatology Department, Hassan II University Hospital as she presented with morning stiffness, arthralgias, symmetric arthritis of the wrists, ankles, bilateral sacroiliitis, enthesitis and inflammatory back pain. The patient had cervical lymphadenopathy with fever and erythema nodosum. Laboratory results were as follows: ESR 25 mm/h and C-reactive protein 13 mg/L while anti-nuclear antibodies, rheumatoid factor, human immunodeficiency virus and angiotensin converting enzyme were negative. The intradermal skin test for tuberculosis reading was 20 mm which is considered strongly positive. Histological report of cervical node tissue revealed granulomatous lesions compatible with tuberculosis. No alteration was observed in the radiographies of chest and the affected joints. MRI of sacroiliac joint and spine was normal. Spondyloarthritis and rheumatoid arthritis were ruled out. Therapy with pyrazinamide, isoniazide and rifampicin was started after which the arthritis resolved in a few days. The diagnosis of Poncet’s disease was confirmed. Conclusion The differential diagnosis between Poncet’s disease and autoimmune inflammatory joint diseases is a clinical challenge. However, Poncet’s disease should be considered as a differential diagnosis for patients with fever and arthritis of unknown cause, particularly if active tuberculosis is suspected.