Mastoiditis is an infection of the mastoid bone of the skull.

Mastoiditis is usually a consequence of a middle ear infection (acute otitis media). 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.

Mastoiditis most commonly affects children. Before antibiotics, mastoiditis was one of the leading causes of death in children. Now it is a relatively uncommon and much less dangerous disorder.

• Ear pain or discomfort
• Swelling behind ear, may cause ear to stick out
• Redness of the ear or behind the ear
• Fever, may be high or suddenly increase
• Headache
• Drainage from the ear

An examination of the head may indicate mastoiditis. A skull X-ray or head CT scan or CT of the ear may show an abnormality in the mastoid bone. A culture of drainage from the ear may show bacteria.

Mastoiditis may be difficult to treat because it is difficult for medications to reach deep enough into the mastoid bone. It may require repeated or long-term treatment. Antibiotics by injection, then antibiotics by mouth are given to treat the infection.

Surgery to remove part of the bone and drain the mastoid (mastoidectomy) may be needed if antibiotic therapy is not successful. Surgical drainage of the middle ear through the eardrum (myringotomy) may be needed to treat the underlying middle ear infection.

Mastoiditis is curable with treatment but may be hard to treat and may recur.

• Partial or complete hearing loss
• Destruction of the mastoid bone
• Facial paralysis
• Meningitis
• Spread of infection to the brain or throughout the body
• Epidural abscess

Call your health care provider if symptoms indicate mastoiditis.

Call for an appointment with your health care provider if a known ear infection does not respond to treatment or is followed by new symptoms, or if symptoms do not respond to treatment.

Prompt and complete treatment of ear infections reduces the risk of developing mastoiditis.

Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head & Neck Surgery. 4th ed. St Louis, Mo; Mosby; 2005:3019-3020.

Mandell GL, Bennett JE, Dolin R. Principles and Practice of Infectious Diseases. 6th ed. London: Churchill Livingstone; 2005:771.