Prevalence of fungal infection on foot in diabetic patients and correlation between diabetic ulcer and fungal infection on foot

Object: The purpose of this study was to determine the prevalence of fungal infection and ulcer on the feet of diabetic patients and the existence of correlation between ulcer and fungal infection. Methods: A total of 21,693 outpatients diagnosed as diabetes mellitus at the department of endocrinology of 32 hospitals were examined. The diabetic patients with foot problems were consulted to the department of dermatology. Physical examination and KOH preparation were performed. Results: 13,271 patients had certain kinds of foot problem, accounting for 61.2% of 21,693 diabetics examined. Of these, fungal foot disease were found in 10,403 that constituted 78.4% (48.0% of the entire diabetic population). Tinea pedis was the diagnosis in 6,496 (29.9%), onychomycosis in 7,783 (35.9%), and coexistence was in 3,883 (17.9%). Foot deformity was in 1,346 (6.2% of diabetics; 10.1% of foot disease), non-palpable pulse in 1,051 (4.8%; 7.9%), and foot ulcer was in 425 (2.0%; 3.2%), following in a descending order of frequency. Odds ratios for diabetic foot ulcer were 2. 5 in patients with the foot deformity, 1.6 with fungal foot disease and 2.2 with non-palpable pulse. Conversely, Odds ratios for fungal foot disease were 2.5 with foot deformity, and 1.6 with foot ulcer. A total of 5,486 patients paid a visit to the department of dermatology. Of these, 4,519 patients were diagnosed with fungal infection through physical examination and KOH smear by dermatologists. The population comprised of 2,272 males and 2,247 females, showing similar prevalence between sexes. However, age did have positive correlation regarding prevalence of fungal foot disease. The number of diabetic patients with toenail problems was 3,847 patients (70%) and onychomycosis was proven mycologically in 3,276. Onychomycosis of distal subungal type was the most common clinical finding, most frequently involving the great toenails. Abnormal skin findings of the foot were seen in 3,885(70.8%) and tinea pedis was found in 3,209 (58.5%), most commonly involving the soles. Conclusion: This study showed that fungal infection might be regarded as a risk factor of foot ulcer. Treatment of fungal infection in diabetic patients might prevent diabetic foot disease such as ulcer and reduce the disability, morbidity and mortality in diabetic patients.