Type of publication:
Conference abstract
Author(s):
*Khan A.; *Jain D.
Citation:
British Journal of Dermatology. Conference: 104th Annual Meeting of the British Association of Dermatologists, BAD 2024. Manchester United Kingdom. 192(Supplement 1) (pp i157), 2024. Date of Publication: July 2024.
Abstract:
Mycobacterium marinum is a waterborne, atypical mycobacterium that is known to cause infection in fish, mice and bats. M. marinum in humans is rare and can manifest as a skin/soft tissue infection following exposure of damaged skin to polluted water from aqueous environments such as swimming pools, wells, rivers and fish tanks. We report the case of a 73-year-old White man with a history of collagenous colitis on treatment with infliximab. He presented with pustules, ulcerated plaques and nodules on his left wrist and left deltoid as well as some nodules on the right forearm in a sporotrichoid distribution following a second infliximab infusion. A skin biopsy revealed prominent dermal abscess formation with extension of acute inflammation into the subcutis with fat necrosis. Small granulomas were also seen at the edges without caseating necrosis. Numerous acidfast bacilli were present on a Ziehl-Neelsen stain in keeping with mycobacterial infection. He was started empirically on rifampicin, ethambutol and clarithromycin; however, minimal improvement was noted. A subsequent mycobacteria microscopy, culture and sensitivity revealed sensitivity to ciprofloxacin, and fortunately his skin responded well to this. Tumour necrosis factor (TNF)-alpha inhibitors such as infliximab are widely used treatments in managing chronic inflammatory dermatoses as well as inflammatory bowel disease. These agents increase the risk of granulomatous disease. A diagnosis of M. marinum is challenging and multiple biopsies and tissues cultures may be necessary for identifying the correct diagnosis. Although this case did not have any typical exposures to M. marinum, it highlights the importance of screening and educating patients regarding the risks of certain environmental exposures prior to commencing anti-TNF treatments.
