A potassium hydroxide (KOH) test is done to determine whether a fungus is causing a skin infection. Samples from an infected area are treated with KOH, which dissolves skin cells and leaves behind fungus cells (if any are present) that can been seen with a microscope.

The KOH test may be used to diagnose fungal infections, such as thrush, tinea versicolor, and ringworm.

Current as of: February 20, 2015

Author: Healthwise Staff

Medical Review: E. Gregory Thompson, MD - Internal Medicine & Randall D. Burr, MD - Dermatology