Exams and Tests

Doctors can often easily recognize ringworm when there is a distinct ringworm-patterned rash. Your doctor will probably also look at a hair or skin sample (KOH preparation) under a microscope to determine whether a fungus is present.

Tests used for ringworm of the scalp or beard include:

• A KOH (potassium hydroxide) preparation, which your doctor can use to find out whether the skin condition is caused by a fungus.
• A fungal culture (skin culture), which your doctor usually will do only if diagnosis is difficult or the skin condition is not responding to treatment. The test results may take 4 to 6 weeks.

Early Detection

If someone in your family has ringworm of the scalp or beard, talk to your doctor about whether other family members should be examined. It is quite common for one family member to spread the fungus to other family members.