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.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.