LAB TEST
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
Your health care provider scrapes the problem area of your skin using a needle or scalpel blade. The scrapings from the skin are placed on a microscope slide. Liquid containing the chemical potassium hydroxide (KOH) is added. The slide is then examined under the microscope. KOH helps dissolve much of the cellular…
How to Prepare for the Test
There is no special preparation for the test.
How the Test will Feel
You may feel a scratching sensation when the provider scrapes your skin.
Why the Test is Performed
This test is done to diagnose a fungal infection of the skin.
Normal Results
No fungus is present.
What Abnormal Results Mean
Fungus is present. The fungus may be related to ringworm , athlete's foot , jock itch , or another fungal infection. If the results are uncertain, a skin biopsy may need to be done.
Risks
There is a small risk of bleeding or infection from scraping the skin.
References
Babel DE. Fungal studies (and scabies): collection procedures and tests. In: Fowler GC, ed. Pfenninger and Fowler's Procedures for Primary Care . 4th ed. Philadelphia, PA: Elsevier; 2020:chap 17. Fitzpatrick JE, High WA, Kyle WL. Diagnostic techniques. In: Fitzpatrick JE, High WA, Kyle WL, eds. Urgent Care…
This is a summary. Read the full article at www.ucsfbenioffchildrens.org (reviewed 07/06/2023).
This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.