A 15 year old girl presented with painful, weeping lesions on both lower limbs. She returned from Ethiopia the day before the hospital visit after having stayed for 40 days. There was a history of injury to her right ankle 3 weeks ago and was treated with oral antibiotics. The wound started to heal but subsequently became itchy and started discharging blood stained fluid. A week later similar lesions developed on her left lower limb. She was born in UK and had all her immunisations. Swab from lesions grew group A betahemolytic streptococcus and non-toxigenic Coryne bacterium diphtheriae. She was initially started on Penicillin and Flucloxacillin. Erythromycin was added after the culture results, as C.diphtheriae was penicillin resistant. She made a complete recovery following 7 days of antibiotics.
C.diphtheriae is a non-sporulating, non-encapsulated and non-motile gram positive bacillus.1 The epidemiological significance and mechanism of pathogenicity of nontoxigenic C. diphtheriae is unclear. In Australia, seven cases of endocarditis due to non-toxigenic C. diphtheriae have been reported.2 Cutaneous diphtheria can be caused by both toxigenic and non-toxigenic strains and the lesions usually appear on exposed parts. The lesions start as vesicles and quickly form small, clearly demarcated ulcers.3 Symptomatic infections with non-toxigenic C. diphtheria are rare but when identified needs appropriate treatment. There is no need to carry out clearance swabs or to trace contacts of these individ.uals.4 Skin ulcers not responding to conventional antibiotic treatment should be investigated for rarer causes such as cutaneous diphtheria.
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