Safety and efficacy of tinea pedis and onychomycosis treatment in people with diabetes: a systematic review

BACKGROUND Effective treatment of tinea pedis and onychomycosis is crucial for patients with diabetes as these infections may lead to foot ulcers and secondary bacterial infections resulting in eventual lower limb amputation. Although numerous studies have assessed the effectiveness of antifungal drug and treatment regimens, most exclude patients with diabetes and examine otherwise healthy individuals. While these studies are useful, results cannot necessarily be extrapolated to patients with diabetes. The purpose of this study was to therefore identify the best evidence-based treatment interventions for tinea pedis or onychomycosis in people with diabetes. METHODS The question for this systemic review was: 'what evidence is there for the safety and/or efficacy of all treatment interventions for adults with tinea pedis and/or onychomycosis in people with diabetes'? A systematic literature search of four electronic databases (Scopus, EbscoHost, Ovid, Web of Science) was undertaken (6/1/11). The primary outcome measure for safety was self-reported adverse events likely to be drug-related, while the primary outcome measures assessed for 'efficacy' were mycological, clinical and complete cure. RESULTS The systematic review identified six studies that examined the safety and/or efficacy of treatment interventions for onychomycosis in people with diabetes. No studies were identified that examined treatment for tinea pedis. Of the studies identified, two were randomised controlled trials (RCTs) and four were case series. Based on the best available evidence identified, it can be suggested that oral terbinafine is as safe and effective as oral itraconazole therapy for the treatment of onychomycosis in people with diabetes. However, efficacy results were found to be poor. CONCLUSIONS This review indicates that there is good evidence (Level II) to suggest oral terbinafine is as safe and effective as itraconazole therapy for the treatment of onychomycosis in people with diabetes. Further research is needed to establish the evidence for other treatment modalities and treatment for tinea pedis for people with diabetes. Future efforts are needed to improve the efficacy of treatment intervention.