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Viral lesion culture
Viral lesion culture


Skin lesion KOH exam

Definition:

The skin lesion KOH exam is a test to diagnose a fungal infection of the skin .



Alternative Names:

Potassium hydroxide examination of skin lesion; Fungal wet prep



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 Values:

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.



What the risks are:

There is a small risk of bleeding or infection from scraping the lesion.




Review Date: 4/15/2009
Reviewed By: Jonathan Kantor, M.D., North Florida Dermatology Associates, Jacksonville, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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