J. Yeon1, H. Fallah1,2, R. Chan3
The incidence of non-tuberculous mycobacteria (NTM) has increased in recent years. Of signiﬁcance is NTM related soft tissue and skin infections which have coin- cided with a surge of cosmetic related procedures. NTM also known as atypical mycobacteria, are ubiquitous in the environment. Delay in the diagnosis of NTM in not uncom- mon. Standard microscopy and culture usually has a low yield, and NTM does not respond to conventional antibi- otics. We report a case of a 34-year-old female patient who ﬁrst presented to the Emergency department with left jaw swelling and tenderness after Botulinum toxin was injec- tion into her masseters for teeth grinding four months prior. A small lump initially developed and gradually increased 2–3 weeks after the initial injection. Despite a course of oral phenoxymethylpenicillin and clindamycin, there was no improvement to the tender and painful lesion. On physical examination, there was a tender ﬂuctu- ant nodule at the site of the Botox injection on the left angle of jaw. A skin biopsy performed showed changes suggesting an infection with mixed granulomatous inﬂam- mation extending to the deep dermis, comprising foamy histiocytes, lymphocytes, plasma cells, neutrophils and occasional granulomas. Ziehl-Neelsen staining was nega- tive for acid fast bacilli. The lesion was aspirated and cul- tured; Mycobacterium immunogenum was isolated. This case highlights the potential hygiene-related aetiology of NTM and reﬂects the need for stronger infection control practices in cosmetic practices.