LAUSR

A 12-year-old girl of Samoan heritage presented acutely to the emergency department with painful, swollen, erythematous, punched out ulcerations and crusting on her lower lip (Fig. 1) leading to difficulty eating and drinking. She was also identified to have multiple well-circumscribed grey hyperkeratotic papules on her arms and legs (Fig. 1). These limb lesions first appeared during her 1-month visit to Samoa and were assumed to be mosquito bites as she was residing in a rural farm area. Upon return to Australia, she developed low-grade fevers, prompting general practitioner review. The lesions were initially diagnosed and treated as infected insect bites with cephalexin, with minimal effect. The duration of time from appearance of initial skin lesions to presentation with oral lesions was 3 weeks. Clinically, she was afebrile, and there was no clinical pulmonary, gastrointestinal, cardiac and neurological involvement. She had no significant past medical history, and her vaccinations were up to date according to the Australian Immunisation Schedule. A lip microbiological swab cultured Corynebacterium diphtheriae, Staphylococcus aureus and Streptococcus pyogenes. Skin histology from a punch biopsy of her arm lesions also grew C. diphtheriae. The polymerase chain reaction analysis for the diphtheria toxin was negative. A subsequent pharyngeal swab was negative, and blood tests did not indicate any systemic organ involvement. She was initially treated with flucloxacillin, with the addition of 6-hourly 10 mg/kg erythromycin when C. diphtheriae was confirmed. Erythromycin was continued for a total of 14 days. At the 2-week follow-up, the lesions had completely resolved, and a repeat swab indicated clearance of the disease; thus, antibiotics were ceased. The patient had travelled with her five younger siblings to Samoa, all of whom, on review, had similar appearing cutaneous lesions (Figs. 2 and 3). These were swabbed, and all were commenced on erythromycin treatment empirically. Three of the siblings had C. diphtheriae (non-toxigenic), S. aureus and S. pyogene isolated. Given the non-toxigenic nature of the C. diphtheriae, no public health tracing was conducted.