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

Mastoiditis is usually caused by 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 usually 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 condition.

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

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

• CTscan of the ear
• Head CT scan

A culture of drainage from the ear may show bacteria.

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.

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

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

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

Call your health care provider if you have symptoms of mastoiditis.

Call for an appointment with your health care provider if:

• You have an ear infection that does not respond to treatment or is followed by new symptoms
• Your symptoms do not respond to treatment

Promptly and completely treating ear infections reduces the risk of mastoiditis.

Chole RA, Sudhoff HH. Chronic otitis media, mastoiditis, and petrositis. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2010:chap 139.

Klein JO. Otitis externa, otitis media, and mastoiditis. In:Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap57.

O’Handley JG, Tobin EJ, Shah AR. Otorhinolaryngology. In: Rakel RE, ed. Textbook of Family Medicine. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 19.