THU0587 TB OR NOT TB? THIS IS THE QUESTION. CASE REPORT OF AN EXTRAPULMONARY TUBERCULOUS ARTHRITIS.

Background:Tuberculous (TB) arthritis consists of 1-3% of all TB cases, whereas TB tenosynovitis & bursitis account for 1%. Primarily it involves large joints but occasionally smaller non-weight-bearing joints. Diagnosis is usually delayed due to lack of awareness, radiographic findings & constitutional or pulmonary involvement.Objectives:We aim to increase rheumatologists awareness to detect possible TB etiology for arthritis & tenosynovitis.Methods:Our case is a 32 years old male complaining of polyarthritis of wrists, MCPs, ankle joints 4 months prior to presentation. Patient was referred as diagnosed rheumatoid patient resistant to treatment based on clinical presentation & laboratory investigation. His lab. was as follows; ESR 76 mm/hr, CRP 56.6 mg/L, RF 181.8 IU/ml, Serum creat 0.8 mg/dL, SGOT 20 SGPT 22, FBS 94, Uric acid 5.4, Hepatitis & HIV negative. CBC showing Hb 14.1 g/dL, TLC 7030/ml & platelets 289000/ml. There was no history of genitourinary, gastrointestinal manifestations, oral/genital ulcers, ophthalmological, mucocutaneous, cardiac, pulmonary, hepatic nor renal manifestations. The treatment at time of presentation was Methotrexare 25mg/week IM injection, Leflunamide 20mg/d & low dose steroids, prednisolone 5mg/d. Patient was referred to our department to assess activity, perform musculoskeletal ultrasound to the various involved joints. Hence, expected by referring physician to shift from DMARDs to biologic treatment.Results:MSUS study following eular guidlines showed active synovitis in both radiocarpal & midcarpal joints bilaterally grade II by doppler signal (figure 1). Other active synovitis in multiple MCPs as well as tenosynovitis of Peroneus longus and brevis bilaterally was detected (figure 1). The swelling aound the ankle was alarming though the other swollen joints seemed to be consistent with a case of RA in activity. This swelling revealed a well-defined hypoechoic heterogeneous cystic fluid collection with posterior through-transmission (figure 2) & hyperechoic hyperemic wall on PD imaging opposite medial malleolous of right fibula. The laboratory investigations prior to shifting patient had to included TB tests, tuberculin test and PCR following the positive result that we found in the skin test. Aspiration was performed from the cystic swelling and sent for clinical pathology analysis. Thick yellowish fluid aspirate on cytology revealed moderately cellular mainly of PMN cells, neutrophils, nuclear debris in proteinaceous background no atypical or malignant cells were found. As regards bacteriology no pus with no growth (both aerobic & anerobic). These results warranted us to perform a culture for atypical bacteria and revealed growth of mycobacterium tuberculosis. AntiTB therapy was started for 9 months in the form of 2 months of isoniazid (INH) and rifampicin (RIF), pyrazinamide (PZA) and ethambutol (EMB) followed by 7 months of INH and RIF. Excision of the synovial cyst was done on the spot.Figure 1.Figure 2.Conclusion:Extrapulmonary TB is usually diagnosed late due to a reduced diagnostic suspicion. A variant of 8 - 60% of TB cases are +ve for RF & 7–39% +ve for ACPA. Musculoskeletal manifestations occur in approximately 1-3% of TB cases. Of these, spondylitis and arthritis are the most frequent, whereas bursitis and tenosynovitis are exceptional. Extraarticular cystic masses occur in tuberculous arthritis. Mixture of septic tuberculous arthritis and Poncet’s disease is rare but documented.References:[1]Varshney et al. Isolated tuberculosis of Achilles tendon. Joint Bone Spine, 74 (2007): 103-106.[2]Lee et al.Tuberculous Tenosynovitis and Ulnar Bursitis of the Wrist.Ann Rehabil Med. 2013 Aug; 37(4): 572–576.[3]Rekha et al. Tuberculous Olecranon Bursitis. Case Reports in Clinical Medicine, 2014, 3, 281-285.[4]Kim et al. Tuberculosis of the trochanteric bursa: a case report. Journal of Orthopaedic Surgery 2014;22(1):126-9.Disclosure of Interests:None declared