A comparison of conventional rapid methods in diagnosis of superficial and cutaneous mycoses based on KOH, Chicago sky blue 6B and calcofluor white stains

Rapid confirmation of dermatomycoses is desirable, as it allows the clinicians to initiate appropriate therapy immediately. In this study, the utility of a novel contrast stain, Chicago sky blue stain, was compared with potassium hydroxide mount and calcofluor white stain to determine the causative fungal elements in the rapid detection method. In this survey, 189 samples of suspected dermatomycosis infections were assessed in 3 incubation times of 30 minutes, 2 hours, and > 6 hours. Positive cases were shown in Chicago sky blue 6B (55%), calcofluor white (53.4%), and potassium hydroxide (36%), with 30-minute incubation. Positive results increased in other incubation times. Sensitivity, specificity, PPV, NPV and accuracy of Chicago sky blue 6B were 97%, 100%, 100%, 96% and 98% and, for potassium hydroxide, they were 66%, 98%, 97%, 98%, 80% versus CFW, respectively. This study provides evidence that the Chicago sky blue 6B stain is a simple, fast and cost-effective method.