BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuSkin lesion KOH examPotassium hydroxide examination of skin lesionThe skin lesion KOH exam is a test to diagnose a fungal infection of the skin.Fungal infection of the skinCandida infection of the skin is a yeast infection of the skin. The medical name of the condition is cutaneous candidiasis.ImageRead Article Now Book Mark Article How the Test is Performed The 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 material. This makes it easier to see if there is any fungus.Potassium hydroxidePotassium hydroxide is a chemical that comes as a powder, flakes, or pellets. It is commonly known as lye or potash. Potassium hydroxide is a caust...Read Article Now Book Mark Article 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.RingwormRingworm is a skin infection due to a fungus. Often, there are several patches of ringworm on the skin at once. The medical name for ringworm is ti...ImageRead Article Now Book Mark Article Athlete's footAthlete's foot is an infection of the feet caused by fungus. The medical term is tinea pedis or ringworm of the foot.ImageRead Article Now Book Mark Article Jock itchJock itch is an infection of the groin area caused by a fungus. The medical term is tinea cruris or ringworm of the groin.ImageRead Article Now Book Mark Article If the results are uncertain, a skin biopsy may need to be done.Skin biopsyA skin lesion biopsy is when a small amount of skin is removed so it can be examined. The skin is tested to look for skin conditions or diseases. A...ImageRead Article Now Book Mark Article Risks There is a small risk of bleeding or infection from scraping the skin.Open ReferencesReferencesChernecky CC, Berger BJ. Potassium hydroxide preparation (KOH wet mount) - specimen. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:898-899.Fitzpatrick JE, High WA, Kyle WL. Diagnostic techniques. In: Fitzpatrick JE, High WA, Kyle WL, eds. Urgent Care Dermatology: Symptom-Based Diagnosis. Philadelphia, PA: Elsevier; 2018:chap 2.AllVideoImagesTogTinea (ringworm) - illustration Ringworm is a common skin disorder, especially among children, but may occur in people of all ages. It is caused by mold-like fungi (dermatophytes).Tinea (ringworm)illustrationTinea (ringworm) - illustration Ringworm is a common skin disorder, especially among children, but may occur in people of all ages. It is caused by mold-like fungi (dermatophytes).Tinea (ringworm)illustration Tests for Skin lesion KOH exam Skin lesion KOH examRelated Information Candida infection of the skin(Condition)Ringworm(Condition)Ringworm of the body(Condition)Athlete's foot(Condition)Jock itch(Condition) Review Date: 6/19/2021 Reviewed By: Ramin Fathi, MD, FAAD, Director, Phoenix Surgical Dermatology Group, Phoenix, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.