The prevalence of dermatophyte infection in well-controlled diabetics and the response to Trichophyton antigen.

The prevalence of dermatophyte infection was assessed in 100 patients with well-controlled insulin-dependent diabetes, and in a control group of 100 non-diabetics matched for age, sex, occupation and sporting activity. Immediate and delayed responses to intradermal testing with Trichophyton antigen were recorded in both groups. The overall infection rate (skin and nails) was 19% in diabetics and 17% in controls. There was a higher infection rate in the skin of diabetics (17%) than in controls (8%), but this was not significant. Nail infection was seen in 12% of diabetics and in 11% of controls. Intradermal testing with Trichophyton antigen gave a higher proportion of both immediate and delayed positive results in diabetics. However, more control patients showed only an immediate positive response or only a delayed one. There was no evidence of an increased infection rate in those with immediate positive responses or of diminished infection rates in those with delayed positive responses, and no correlation with oral Candida infection. These findings applied equally to diabetics and controls.