The KOH (potassium hydroxide) preparation is used to find out
whether a fungal infection is present on the skin.
A sample of skin is taken by lightly scraping the infected
The skin sample is placed on a slide with KOH solution and the solvent DMSO. This solution slowly dissolves the skin cells but not the fungus cells.
The fungus cells can then be seen with a microscope. Color stains may be used
so that the fungus is easier to see.
How this information was developed to help you make better health decisions.