A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal or bacterial infection on the skin or scalp. If there is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally the skin does not fluoresce, or shine, under ultraviolet light.
Review Date 11/4/2020
Updated by: Elika Hoss, MD, Senior Associate Consultant, Mayo Clinic, Scottsdale, AZ. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.