A Case of Erosive Polyarthritis in a Patient Diagnosed With a Suspicion of Atypical Mycobacteria
A 55- year old Saudi female patient newly diagnosed as a case of osteoporosis and polymyalgia rheumatic was presented to the outpatient rheumatology clinic in December 2011 at King Faisal Specialist Hospital and Research Center, in Jeddah, with a month-long history of bilateral hand joints pain and morning stiffness lasting for 1 hour. She had no other joints involvement or any systemic symptoms.\nHand examination revealed tenderness over the metacarpophalangeal (MCPs), proximal interphalangeal (PIPs) and wrists joints but there was no swelling. Laboratory studies showed that WBCs= 12.8 × l (4.00-11.0 x 109/L) erythrocyte sedimentation rate (ESR) =15 mm/hr (<30 mm/hr), C-reactive protein (CRP) = 0.459 mg/dl (0-5mg/dl). Antinuclear antibodies, rheumatoid factor & anti-citrullinated protein peptide antibody (ACPA) were negative. Ultrasound exam of hands showed erosions in the right second MCP and effusion in both second MCPs and wrists joints. At that time she was diagnosed as inflammatory arthritis. Methotrexate 12.5 mg/week, folic acid 5mg/week and 10 mg prednisolone once daily were initiated.\nIn April 2012, she was still complaining of hand joints pain and morning stiffness. Arthritis remained active despite the treatment with methotrexate. A biological treatment was considered. The PPD skin test showed 15 mm reaction and CXR showed left lower lobe nodule. She denied any symptoms suggestive of tuberculosis (TB). Patient was referred to the Infectious Diseases (ID) and Isoniazid (INH) with pyridoxine were initiated. Two weeks later she developed a productive cough, an intermittent fever and a night sweat. A sputum culture and Computed tomography (CT) scans of the chest were arranged.\nIn her follow up in June 2012 with ID service, only one culture showed acid-fast bacilli of atypical mycobacterium further identification grew M. abscessus. Polymerase chain reaction (PCR) for mycobacterium was negative. The patient did not meet the American Thoracic Society (ATS) criteria for NTM []. The sputum culture was repeated. She was maintained on INH. Meanwhile, it was considered that probably she had transient infectious process. In July 2012, a biological treatment was initiated, Etanercept; which is a TNF blocker (Enbrel) administered at a dose of 50 mg subcutaneous every one week.\nOn her follow up in September 2012, she demonstrated improvement in her arthritis but still had nonspecific symptoms with vague history of productive cough, intermittent undocumented fever, weight loss (4 kg) and the new development of chest pain. The decision was made to continue on Enbrel while she was being worked up for the presence of NTM.\nBy the end of September 2012 the repeated culture grew Mycobacterium Avium Complex (MAC) isolation. CT-chest showed left pleural-based granuloma. The ID service evaluation considered M. abscessus as the likely atypical mycobacterium causing the symptoms and MAC was considered as a contamination. Azithromax, ciprofloxacin and doxycycline were initiated as a treatment for M. abscessus. The biological therapy was discontinued.\nIn November 2012, she had the same non-specific complaints of productive cough and intermittent undocumented fever with no improvement on the antibiotic regimen that was given. Ethmbutol was added to add further coverage to include MAC but it was discontinued after one month. The subsequent culture was negative.\nIn December 2012, she newly developed aziothromax allergic reaction in form of gastrointestinal upset. The first culture and sensitivity showed intermediate resistant to Aziothromax. Therefore, linezolid was initiated and Aziothromax was discontinued.\nIn January 2013 with her follow up in rheumatology clinic, her symptoms improved. She gained 2Kg and her appetite was back to normal. She demonstrated significant improvement in her joint symptoms. The ultrasound exam of hands showed mild effusion in her joints. She remained off Enbrel and we decided to continue on the same treatment with follow up.