Skin lesion KOH exam
The skin lesion KOH exam is a test to diagnose a fungal infection of the skin.
How the Test is Performed
The health care provider scrapes the lesion off your skin, using a blunt edge such as the edge of a microscope slide. The scrapings from the skin lesion are placed in liquid containing potassium hydroxide (KOH) and examined under the microscope. KOH destroys all non-fungal cells, which makes it easier to see if there is any fungus present.
How to Prepare for the Test
There is no special preparation for the test.
How the Test Will Feel
You may feel pressure when the doctor scrapes the lesion off your skin.
Why the Test is Performed
This test is done to diagnose a fungal infection of the skin.
Normal Results
Normally, there is no fungus.
What Abnormal Results Mean
The KOH smear shows fungus, which may be related to ringworm, athlete's foot, jock itch, or another fungal infection.
Risks
There is a small risk of bleeding or infection from scraping the lesion.
Alternative Names
Potassium hydroxide examination of skin lesion
Update Date: 5/13/2012
Reviewed by: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
Notice: The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2012, A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.