Extensive cutaneous Mycobacterium abscessus infection due to contaminated insulin delivery system

Abstract

A 48-year-old insulin-dependent diabetic woman presented with multiple lesions at her insulin injection sites. The lesions had gradually appeared and progressively enlarged over a 7-week period. Her background included 27 years of insulin-dependent diabetes mellitus, complicated by micro-vascular disease with early diabetic nephropathy, sensory peripheral polyneuropathy and grade 1 diabetic retinopathy. Diabetic management had been with a basal-bolus regimen of insulin, but with generally poor diabetic control (glycosylated haemoglobin of 10–11%). The lesions were only associated with her isophane insulin (delivered by a Novojet™ pen system) injection sites; her abdominal neutral insulin (Actrapid™) injection sites were unaffected. She denied any constitutional symptoms. Despite rotating her insulin injection sites, improving her injection site hygiene, and using clean insulin needles and canisters, new lesions continued to occur, and empiric oral antimicrobial therapy including flucloxacillin, erythromycin and amoxycillin/clavulanic acid had been ineffective. On examination she was afebrile and appeared well, however she had multiple erythematous, violaceous, non-tender plaques on the anterior aspect of her thighs (Figure 1). There was no associated lymphadenopathy, and her anterior abdominal wall insulin injection sites were unremarkable. Apart from signs of end-organ diabetic disease the remainder of her examination was normal. Figure 1. Left anterior thigh lesions at the infected insulin injection …