Petrositis usually refers to infection of the temporal bone, the bone in the skull that surrounds the ear. This infection goes deep to the inner ear. It is sometimes associated with otitis media (a middle ear infection).
Baloh RW, Jen J. Hearing and equilibrium. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 436.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.