Fungal infections are caused by microscopic organisms (fungi) that can live on the skin. They can live on the dead tissues of the hair, nails, and outer skin layers.
Review Date 5/2/2017
Updated by: David L. Swanson, MD, Vice Chair of Medical Dermatology, Associate Professor of Dermatology, Mayo Medical School, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.