A 37-year-old Caucasian man working as a mechanic presented to the emergency department with a solitary swelling on the right side of his chest wall. He had previously had an incision and drainage of the abscess on the same site while working in the Middle East. He was not diabetic and was immunocompetent. He had injected anabolic steroids in the pectoral muscles for body building in the past. On examination, he had a 5cm x 5cm abscess in the right axilla. It was incised and drained under general anaesthesia and he was discharged home with a course of oral amoxicillin and clavulanate 625mg three times a day for seven days. A routine bacterial culture of the wound showed no significant growth.
The patient presented again a week later with recurrence of the abscess. Further incision and drainage was performed and again the swabs did not yield any bacterial growth. A week later, he presented for a third time with yet another recurrence. The abscesses were erythematous, tender and discharging pus. He underwent further drainage of the abscess cavities. On this occasion, a tissue sample was sent for histology and microbiology analysis. The impression at this time was one of hidradenitis suppurativa (Fig 1).  
These indurated and multiple abscesses required a fourth round of surgery. The histology was reported as 'chronic inflammation with multinucleate giant cells along with foci of caseating necrosis surrounded by granulomas' (Fig 2). There were no acid-fast bacilli demonstrated on special staining. However, the diagnosis was thought to be probable tuberculosis.  
The patient was referred to the respiratory physicians for treatment of tuberculosis. However, the tissue culture isolated a very resistant Mycobacterium fortuitum, and so he was treated with ciprofloxacin 750mg twice daily and doxycycline 200mg daily. He was unable to tolerate ciprofloxacin and was switched to a second line quinolone in the form of moxifloxacin 400mg daily and continued on doxycycline 200mg daily. Unfortunately, he developed side effects with the second quinolone and this was also discontinued. The extensive antibiotic resistance pattern meant there were few oral treatment options. Computed tomography of the chest excluded secondary pulmonary involvement. The respiratory physician referred him back for further surgical excision with a view to obtain clear margins. He was reviewed in the surgical clinic few weeks later. The wound had healed completely (Fig 3). Histology revealed only fibrous scar tissue and no evidence of any granulomatous inflammation.