Mastoiditis is a bacterial infection of the mastoid air cells (small, air-filled cavities located in the mastoid process, which is the bulge in the skull behind the ear).
Mastoiditis, a bacterial infection within the honeycomb-like mastoid process, in most cases results when an ear infection spreads to the mucus membrane surrounding the mastoid process and eventually reaches the walls of the bone itself.
If the infection persists, it may destroy the delicate structures of the mastoid. This can result in hearing loss and, without treatment, continued destruction of bone in the skull.
Mastoiditis most often affects children. Before the advent of antibiotics, it was a common cause of childhood mortality.
Currently, prospects of full recovery are very good. However, if not treated promptly, mastoiditis may lead to further complications, including meningitis, facial paralysis, labyrinthitis, and brain abscess, in addition to hearing loss and bone destruction.
Bacteria that cause mastoiditis include pneumococcus (usually in children under age 6), Hemophilus influenzae, beta-hemolytic streptococci, staphylococci, and gram-negative organisms.
Signs and symptoms of mastoiditis include:
- Dull ache and tenderness in the area of the mastoid process
- Low-grade fever
- Thick, purulent discharge that gradually becomes more profuse
- Postauricular erythema and edema (may push the auricle out from the head)
- Possible conductive hearing loss
- Edema of the tympanic membrane
Treatment of mastoiditis consists of intense parenteral (intravenous or intramuscular) antibiotic therapy.
If bone damage is minimal, myringotomy drains purulent fluid and provides a specimen of discharge for culture and sensitivity testing.
Recurrent or persistent infection, or signs of intracranial complications necessitate simple mastoidectomy. This procedure involves removal of the diseased bone and cleansing of the affected area, after which a drain is inserted.
A chronically inflamed mastoid bone requires radical mastoidectomy - excision of the posterior wall of the ear canal, remnants of the tympanic membrane, and the malleus and incus (although these bones are usually destroyed by infection before surgery). The stapes and facial nerve remain intact.
Radical mastoidectomy, which is seldom necessary because of antibiotic therapy, does not drastically affect the patient's hearing because significant hearing loss precedes surgery.
With either surgical procedure, the patient continues oral antibiotic therapy for several weeks after surgery and hospital discharge.