Definition Mastoiditis is an inflammation within the mastoid bone, which is the bone immediately behind the ear. Mastoiditis is usually caused by an infection.
What is going on in the body? Inflammation that starts in the mastoid itself is quite rare. Mastoiditis is almost always caused by an infection in the middle ear, which is behind the eardrum. Because the mastoid is close to the middle ear, it is easy for middle ear infections, such as acute otitis media, to spread to the mastoid. Chronic or long-lasting mastoiditis lasts for more than 3 months. Acute or shorter-lasting mastoiditis lasts less than 3 weeks.
What are the signs and symptoms of the disease? Signs of mastoiditis may include:
Other signs are usually only seen with acute mastoiditis. These may include:
swelling and redness of the skin behind the ear
significant swelling behind the ear that causes the ear to be pushed forward
a soft, compressible feeling to the bone behind the ear. This means that there is an abscess, or pocket of pus, under the skin.
Chronic mastoiditis does not produce changes over the bone behind the ear. Most of the time, a person with chronic mastoiditis has no symptoms other than occasional pain. When the condition flares up, pus can drain from the ear canal.
What are the causes and risks of the disease? The main cause of acute mastoiditis is untreated or incompletely treated middle ear infection, or acute otitis media. The main cause of chronic mastoiditis is a perforated eardrum combined with a long-lasting infection in the middle ear, known as chronic otitis media. Benign ear growths, particularly cysts known as cholesteatomas, are also frequent causes.
What can be done to prevent the disease? Antibiotics for ear infections and methods to drain fluid from the ears can help prevent most cases of mastoiditis. Children with ear infections should be treated early with antibiotics. It is important that a person take the full course of the antibiotic to prevent mastoiditis. Also, children who have frequent infections should be monitored in an effort to prevent mastoiditis and ear cysts from developing.
How is the disease diagnosed? To make the diagnosis, the doctor will first examine the person's ear. The doctor will also order x-ray tests. If the infection is severe, the x-ray tests will show damage or infection of the bone.
What are the long-term effects of the disease? Long term, acute mastoiditis can lead to:
meningitis, or inflammation of the lining of the brain, which may cause permanent brain damage or death
a blood clot in the veins that drain the blood from the brain
an abscess or pocket of pus under the skin, in nearby muscles, or even in the brain. A brain abscess can result in permanent brain damage or death.
scarring in the ear or mastoid
What are the risks to others? There are no risks to others, as the condition is not contagious.
What are the treatments for the disease? Treatment for acute mastoiditis includes the insertion of an ear tube through the eardrum to allow drainage of infected fluid. A cut can also be made in the eardrum for the same purpose. Antibiotics to treat the infection are also part of treatment. If the infection has reached the stage where bone is being destroyed, surgery may be needed to remove part of the mastoid bone.
The first step in treating chronic mastoiditis is oral or topical antibiotics. If this does not clear up the problem, surgery is needed to remove the diseased part of the mastoid and repair the eardrum. If an ear cyst exists, the cyst is removed and the eardrum repaired. If there has been damage to the bones of the middle ear, this will be repaired as well.
What are the side effects of the treatments? Placement of the drainage tubes can result in complications such as long-lasting holes in the eardrum, ear drainage, and rarely, deafness. Side effects from surgery to remove the mastoid can include damage to nearby structures such as:
What happens after treatment for the disease? Most cases of acute mastoiditis clear up once the ear tube is inserted and antibiotics are started. The tube is left in until it falls out by itself, usually within 6 to 12 months.
If surgery for chronic mastoiditis is successful, the hole in the eardrum will heal closed. The person's hearing will improve, though it may not return to normal in some cases. The ear will stop draining.
How is the disease monitored? An new or worsening symptoms should be reported to the doctor.
Author: Mark Loury, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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