doctors often can easily recognize ringworm by its ring-shaped rash. your doctor will probably also look at a skin sample ( koh preparation ) under a microscope to confirm that fungus is present. tests for ringworm of the skin include: a koh (potassium hydroxide) preparation. this test can help your doctor find out whether a fungus is causing your rash. the doctor will take a sample of your skin by lightly scraping the infected area. the sample is placed on a slide with potassium hydroxide (koh) solution and gently heated. if fungus cells are present the doctor can then see them with a microscope. a fungal culture ( skin culture ). this test can identify the type of fungus that is causing your infection. usually a culture is only done if the diagnosis is difficult or the skin condition is not responding to treatment. this test may take up to 4 weeks because it takes time for the fungus to grow. webmd medical reference from healthwise this information is not intended to replace the advice of a doctor. healthwise disclaims any liability for the decisions you make based on this information. © 1995-2011 healthwise incorporated. healthwise healthwise for every health decision and the healthwise logo are trademarks of healthwise incorporated.
what exams and tests help doctors to evaluate or test people for ringworm of the skin?