OverviewMastoiditis is an infection of the bony air cells in the mastoid bone, located just behind the ear. It is rarely seen today because of the use of antibiotics to treat ear infections. This child has noticeable swelling and redness behind his right ear because of mastoiditis.
Update Date 4/21/2015
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.