Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 10 6 2019 02 10 433 440 EN Parvaneh Afshar Research and Development Unit of Referral Laboratory, Mazandaran University of Medical Sciences, Sari, Iran Lale Vahedi Department of Pathology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran AND Gastrointestinal Cancer Research Center, Mazandaran University of Medical Sciences, Sari, Iran Hamed Rouhanizadeh Research and Development Unit of Referral Laboratory, Mazandaran University of Medical Sciences, Sari, Iran AND Department of Pediatrics, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran 2018 08 14 2018 11 03 Background and Objectives: 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. Materials and Methods: In this survey, 189 samples of suspected dermatomycosis infections were assessed in 3 incubation times of 30 minutes, 2 hours, and > 6 hours. Results: 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. Conclusion: This study provides evidence that the Chicago sky blue 6B stain is a simple, fast and cost-effective method. https://ijm.tums.ac.ir/index.php/ijm/article/view/1866 https://ijm.tums.ac.ir/index.php/ijm/article/download/1866/1103