Clinico-mycological study of dermatophytosis among diabetic and non-diabetic patients in a tertiary level hospital – a comparative study

AbstractDermatophytosis is a major public health concern in India, especially in recent years, with an alarmingly rising trend, particularly with relation to recurrent and chronic infection. The number of studies examining the relationship between an individual's glycemic status and the development of dermatophytoses, and a comparison of the evolving species trend between diabetic and non-diabetic patients infected with dermatophytes, is limited. Our aim was to study and compare the clinical and mycological aspects of dermatophytosis among diabetic and non-diabetic patients and to compare the culture isolates in both groups. This study included 378 patients of clinically suspected dermatophytosis, divided into two groups of 189 known diabetics and non-diabetics each. We subsequently analysed and compared the demographics, clinical data, potassium hydroxide (KOH) mount, calcofluor white staining, and fungal culture results of all patients in both groups. Among the 378 patients, the male: female ratio was 1.2:1. Diabetic patients had a significantly greater extent of involvement and higher rates of recurrence when compared to the non-diabetics. The overall positivity rate was higher in Calcofluor white staining (77.8%) as compared to KOH (57.7%) in both non-diabetics and diabetics. Trichophyton mentagrophytes was the most common isolate(47.6%) in both diabetic (55.0%) and non-diabetic (61.4%) patients, followed by Trichophyton rubrum (31.8% & 29.6% respectively). The overall specificity and sensitivity of the study may have been affected by the possibility that KOH mount findings might have been misinterpreted as false negatives due to cognitive bias and inter-personal observer variance. Due to purposive sampling, we were unable to analyse and compare the total prevalence of dermatophytosis in diabetics and non-diabetics. The pattern of dermatophytosis is comparatively more chronic and severe in diabetics compared to non-diabetics. Trichophyton mentagrophytes was the most common culture isolate in both the groups. There was no change in species isolate between both the groups. Calcofluor white staining can potentially be used as the initial method of choice for the diagnosis of dermatophytosis as it has significantly outperformed the conventional KOH mount.