In December 2011, he presented with several month history of multiple episodes of epistaxis and sensation of left nasal fullness. Examination revealed a left intranasal mass which was excised. It is unclear where the patient acquired the MH, given it is reported across all continents,[2] however it was noted in the preceding 12 months he had Raf inhibitor travelled to South-East Asia (Thailand and Vietnam) and to Queensland (Mackay and Whitsundays).

He continues to work in administration in the seafood industry and occasionally visits fish factories in industrial estates and cities worldwide. Tissue histology from the intra nasal lesion showed acid fast bacilli, which was initially thought to be Mycobacterium leprae and initial empirical antibiotic treatment for consisted of rifampicin, dapsone and clofazimine. One month later an analysis of the Mycobacterium DNA with polymerase chain reaction (PCR) identified the organism as MH and his ITF2357 antibiotic regimen was altered to clarithromycin, ciprofloxacin, rifamipicin and dapsone. Dapsone was continued as a treatment for both the Mycobacterium and as Pneumocystis

jiroveci prophylaxis. At the same time, prednisolone dose was increased from 5 to 50 mg daily, to suppress reactive inflammation at the site of infection. Despite this, he experienced increased nasal pain which gradually resolved over the subsequent two weeks. The introduction of rifampicin necessitated close monitoring of tacrolimus trough levels. He required an increase in his tacrolimus dose from 3 mg twice daily to 8 mg twice daily, in order to maintain trough levels between 4–6 μmol/L. After 13 months of antimicrobial therapy, he complained of fatigue and exertional dyspnoea and was noted to be pancytopaenic (haemoglobin 87 g/L, white cell count 3.6 × 109/L and platelets 133 × 109/L). ‘Blister and bite’ cells seen on blood film implicated dapsone as the likely cause although notably he was not glucose-6-phosphate Cyclic nucleotide phosphodiesterase dehydrogenase deficient. Serial computed tomography (CT) showed size reduction of bilateral

chronic mucous retention cysts (Fig. 1). Given the apparent resolution of the intranasal masses on CT, his antibiotic therapy was stopped and haematological parameters normalised. He had completed 13 months of treatment. Two weeks after stopping antibiotics, the patient noted mild hand swelling and bilateral wrist pain. Two months later he complained of bilateral migratory polyarthralgia of his hands, was noted to have painful swollen fingers, one episode left iritis with painful red eye and left achilles tendonitis. He was trialled on a two-week course of 25 mg prednisolone for possible inflammatory arthritis with no improvement. HLA B27 and rheumatoid factor were negative. Over the ensuing two months, he developed multiple, painless, non-discharging erythematous nodules over his right fingers, left elbow and left lateral malleolus (Fig. 2).