Mastoiditis

Definition of Mastoiditis

Mastoiditis is an infection of the mastoid bone of the skull. The mastoid is located just behind the outside ear.

Causes, incidence, and risk factors

Mastoiditis is usually caused by a middle ear infection (). The infection may spread from the ear to the mastoid bone of the skull. The mastoid bone fills with infected materials and its honeycomb-like structure may deteriorate.

Signs and tests

An examination of the head may reveal signs of mastoiditis. The following tests may show an abnormality of the mastoid bone:

Treatment

Mastoiditis may be difficult to treat because medications may not reach deep enough into the mastoid bone. It may require repeated or long-term treatment. The infection is treated with antibiotics by injection, then antibiotics by mouth.

Expectations (prognosis)

Mastoiditis is curable with treatment. However, it may be hard to treat and may come back.

Review

Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Seth Schwartz, MD, MPH, Otolaryngologist, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 8/3/2010

Mastoiditis - side view of head
Mastoiditis - redness and swelling behind ear
Mastoidectomy  - series

ADAM Medical Encyclopedia

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