This photograph shows a nit, or tiny white egg sack, attached to the shaft of a human hair. Image courtesy of D. Scott Smith, MD, MSc, DTMH.
Review Date 2/24/2022
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.