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R apid diagnosis of superficial dermatomycoses is important so that treatment can be initiated without delay. We compared a new contrast stain with the routine test of potassium hydroxide (KOH) wet mount and culture for the diagnosis of dermatophytic and candidal dermatomycoses.Methods. Skin scrapings were taken from outpatients with superficial dermatomycoses and cultured in Sabouraud dextrose agar with cycloheximide. They were then evaluated under a microscope using both the KOH wet mount technique and the new contrast stain. Two investigators read the slides together but were blinded to all other test results.The new contrast stain contains 1% Chicago sky blue 6B and 8% KOH as the clearing agent. Staining was performed as previously described. 1 Slides were scanned at original magnification ϫ10 to locate blue-staining fungal hyphae. Dermatophytes were confirmed at original magnification ϫ40 on the finding of septate filaments. Candidal yeasts were detected as refractile oval budding yeast cells and/or pseudohyphae after lowering the condenser. Candidal slides were returned to the humidifying chamber and read again the following day to detect any change in staining intensity.A 20% KOH solution was used for the KOH wet mount, and microscopic examination was performed in the usual manner.

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R apid confirmation of onychomycosis is desirable to differentiate it from nonfungal causes of nail dystrophy and to initiate appropriate therapy. In this study, we compared the performance of Chicago Sky Blue (CSB) stain with that of routine potassium hydroxide (KOH) preparation, using culture as the standard, in the diagnosis of onychomycosis. Methods. Nail specimens from patients with a clinical diagnosis of onychomycosis were analyzed with CSB stain, KOH preparation, and Sabouraud dextrose agar culture with added antibiotics. Patients were selected on a random sequential basis. Scrapings were taken from the affected nail surface with a blunt scalpel, and subungual debris was obtained with an eye curette. Nail clippings were taken to include subungual debris as far proximal as was tolerable, and scrapings were taken from their undersurface for tests. Slides for CSB stain were fixed with acetone and left to dry. A drop of 20% KOH was added, and the slides were left to sit at room temperature for 20 to 30 minutes before adding a drop of CSB stain. The slides were examined 10 minutes later with an Olympus BX41 microscope (Olympus, Center Valley, Pennsylvania) at ϫ10, ϫ40 and where necessary, under oil immersion at ϫ100 magnification. The 20% KOH prepared slides were examined after 20 minutes at ϫ10 and ϫ40 magnifications with the condenser lowered.

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