Toe web malodorous maceration with well-demarcated punch-out edge.

Dear Editors, A 53-year-old diabetic man was referred to us for malodorous maceration on the plantar surface of his toe webs and metatarsal pads. The lesions initially appeared as mild erythemas 2months before this consultation, and then progressed to be erosions, oozing, exudation and maceration. The patient was treated with oral itraconazole 100mg daily and other topical antifungal creams for 1month, but failed. He was otherwise healthy and his past medical history was non-contributory. Physical examination revealed beefy-red maceration with a well-demarcated punch-out edge at the interdigital spaces of the feet and metatarsal pads. It attenuated towards the dorsal areas of the feet with peripheral eczematous eruptions (Figure 1). A fruity, acidic odour emanated from the exudation. Peripheral WBC, serum complement, immunoglobulins as well as lymphocyte CD4 and CD8 were all within normal limits. Fasting blood glucose was 7⋅2mmol/l. Microscopic examinations of dermatophytes and yeasts were all negative. Pseudomonas aeruginosa was identified in a bacteriologic culture of a swab from one of the erosions (Figure 2). These findings were most consistent with the diagnosis of gram-negative toe web infection (GNTWI) caused byP. aeruginosa. Guided by the results of in vitro antibiotic susceptibility testing, the patient was treated with ciprofloxacin 3 g intravenously every day for 7 days, and was instructed to soak his feet in the herbal decoction simultaneously (Rhei radix et rhizome; Scutellariae radix; Coptidis rhizome; Phellodendri chinensis cortex) twice daily. The infection improved markedly in 2weeks with rapid resolution of maceration.