Practical tip: Chicago Sky Blue (CSB) stain can be added to the routine potassium hydroxide (KOH) wet-mount to provide a color contrast and facilitate the diagnosis of dermatomycoses.

Rapid confirmation of dermatomycoses is desirable because it allows the clinician to initiate appropriate therapy without delay. The routine potassium hydroxide (KOH) wet-mount is cheap and rapid to use but this method lacks a color contrast. We offer a simple practical tip of adding Chicago Sky Blue (CSB) stain to KOH to highlight fungal elements and provide a color contrast that makes reading and interpretation simple, even for the novice.