often the diagnosis of ringworm is obvious from its location and appearance. otherwise skin scrapings for microscopic examination and a culture of the affected skin can establish the diagnosis of ringworm. if the diagnosis is unclear a potassium hydroxide (koh) preparation of a skin scraping can be reviewed under the microscope to confirm the diagnosis of a fungal dermatophyte infection. if a dermatophyte infection is present and the skin problem is misdiagnosed inappropriate treatment might be prescribed that could actually worsen the infection.
how is ringworm diagnosed?