Grand Rounds Vol 8 pages 4–5 Speciality: Rheumatology Article Type: Case Report DOI: 10.1102/1470-5206.2008.0002 ß 2008 e-MED Ltd Mycobacterium chelonae: a rare cause of subcutaneous nodules in a patient on long term corticosteroids Christopher Strickland and Ali S.M. Jawad Rheumatology Department, The Royal London hospital, Bancroft Road, London, E1 4DG, UK Corresponding address: Dr A. Jawad, Rheumatology Department, The Royal London hospital, Bancroft Road, London, E1 4DG, UK. E-mail: alismjawad1@hotmail.com Date accepted for publication 8 January 2008 Abstract Subcutaneous nodules are a common clinical finding. Common causes include rheumatoid nodules, gouty tophi, neurofibromatosis type 1, Madelung’s disease (benign symmetric lipomatosis), Dercum’s disease (adiposis dolorosa) and tuberous xanthomas. Other causes include: hibernoma, lipoblastoma, angiolipoma, liposarcoma, glomus tumour, leiomyoma, eccrine spiradenoma, neuroma, granular cell tumour and cysts (epidermal, pilar, sebaceous, dermoid). We present a rare cause of subcutaneous nodules in a patient on long term corticosteroids. Keywords Subcutaneous nodules; Mycobacterium chelonae; corticosteroids. Case report A 58-year-old white male presented complaining of a one-month history painful lumps over both his forearms. His past medical history included chronic obstructive pulmonary disease (COPD), osteoarthritis of both knees and osteoporosis secondary to corticosteroid use. He had been taking 10 mg prednisolone daily for the past decade. Examination revealed multiple tender subcutaneous nodules, measuring 1–2 cm in diameter, over the extensor regions of both forearms (Fig. 1). An olecranon bursitis was also present. Initial investigations revealed a normal CRP, ESR and uric acid (urate). His (latex agglutination) rheumatoid factor was negative. Further studies revealed a normal lipid profile; however his IgG was low at 3.4 g/l (normal range 5.5 to 16.5 g/l) and he had a neutrophilia contributing to a raised white count of 15,100/mm 3 . The left olecranon bursa was aspirated revealing amber fluid with a few mononuclear cells but no crystals. There was no bacterial growth on culture. A biopsy of a nodule showed non-specific granulomatous inflammation and was negative for acid fast bacilli. Culture of the nodal biopsy grew Mycobacterium chelonae on culture. He has responded well to clarithromycin and ciprofloxacin; the nodules and the olecranon bursae started to regress but took nearly 4 months before they disappeared. This paper is available online at http://www.grandrounds-e-med.com. In the event of a change in the URL address, please use the DOI provided to locate the paper.