Mastoiditis

An INFECTION in the mastoid BONE behind the EAR. Mastoiditis typically develops as a consequence of untreated or chronic OTITIS media (middle ear infection) when BACTERIA migrate from the middle ear to the adjacent mastoid bone. The rather porous structure of the mastoid bone, which is more a collection of small cavities than a solid structure, provides an ideal habitat for bacteria. Untreated mastoiditis can spread to the nasal SINUSES as well as the MENINGES (membranes surrounding the BRAIN and SPINAL CORD), causing bacterial MENINGITIS, and to the brain itself, causing ENCEPHALITIS. These infections are potentially fatal and require immediate medical treatment. Though mastoiditis was once a common cause of childhood death, it has become rare since the advent of ANTIBIOTIC MEDICATIONS.

PAIN behind the ear, FEVER, and a recent episode of otitis media are the leading indications of acute mastoiditis. The person may also have swelling and tenderness in the mastoid area, and the auricle (external ear) may appear to stick out from the side of the head. Chronic mastoiditis may be subclinical; that is, the infection causes few overt symptoms until it spreads beyond the mastoid or destroys mastoid bone tissue. Diagnosis includes blood tests and cultures of any fluid in the ear to look for signs of infection, and occasionally COMPUTED TOMOGRAPHY (CT) SCAN. In most cases of acute mastoiditis, antibiotic medications and occasionally MYRINGOTOMY (insertion of a small tube through the TYMPANIC MEMBRANE to allow fluid to drain from the middle ear) successfully eradicate the infection. Chronic mastoiditis sometimes requires surgery to open, drain, and occasionally remove portions of the mastoid structure. Severe mastoiditis may require mastoidectomy, in which the surgeon removes the entire mastoid bone. Most people recover fully following treatment, though should have an AUDIOLOGIC ASSESSMENT to determine whether there is residual HEARING LOSS.