Mastoiditis: Difference between revisions

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===Common Causes===
===Common Causes===
*[[MRSA]]
*[[MRSA]]
*[[Otitis media]]
*[[Staphylococcus aureus]]
*[[Staphylococcus aureus]]
*[[Streptococcus pneumoniae]]
*[[Streptococcus pneumoniae]]

Revision as of 16:21, 22 July 2015

Mastoiditis
Side view of head, showing surface relations of bones. (Mastoid process labeled near center.)

Template:Search infobox Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ogheneochuko Ajari, MB.BS, MS [2]

Overview

Mastoiditis is an infection of the mastoid process, the portion of the temporal bone of the skull that is behind the ear. It is usually caused by untreated acute otitis media (middle ear infection) and used to be a leading cause of child mortality. With the development of antibiotics, however, mastoiditis has become quite rare in developed countries, most likely due to antibiotic treatment of otitis media before it can spread. It is treated with medications and/or surgery. If untreated, the infection can spread to surrounding structures, including the brain, causing serious complications.

Epidemiology

In the United States and other developed countries, the incidence of mastoiditis is quite low, around 0.004%, although it is higher in developing countries. The most common ages affected are 6–13 months, as it is during that age that ear infections are most common. Males and females are equally affected.

Pathophysiology

The pathophysiology of mastoiditis is straightforward: bacteria spread from the middle ear to the mastoid air cells, where the inflammation causes damage to the bony structures. The bacteria most commonly observed to cause mastoiditis are Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, and gram-negative bacilli. Other bacteria include Moraxella catarrhalis, Streptococcus pyogenes, and rarely, Mycobacterium species. Some mastoiditis is caused by cholesteatoma, which is a sac of keratinizing squamous epithelium in the middle ear that usually results from repeated middle-ear infections. If left untreated, the cholesteatoma can erode into the mastoid process, producing mastoiditis, as well as other complications.

Causes

Life Threatening Causes

Life-threatening conditions may result in death or permanent disability within 24 hours if left untreated.

Common Causes

Causes by Organ System

Cardiovascular No underlying causes
Chemical/Poisoning No underlying causes
Dental No underlying causes
Dermatologic No underlying causes
Drug Side Effect No underlying causes
Ear Nose Throat No underlying causes
Endocrine No underlying causes
Environmental No underlying causes
Gastroenterologic No underlying causes
Genetic No underlying causes
Hematologic No underlying causes
Iatrogenic No underlying causes
Infectious Disease No underlying causes
Musculoskeletal/Orthopedic No underlying causes
Neurologic No underlying causes
Nutritional/Metabolic No underlying causes
Obstetric/Gynecologic No underlying causes
Oncologic No underlying causes
Ophthalmologic No underlying causes
Overdose/Toxicity No underlying causes
Psychiatric No underlying causes
Pulmonary No underlying causes
Renal/Electrolyte No underlying causes
Rheumatology/Immunology/Allergy No underlying causes
Sexual No underlying causes
Trauma No underlying causes
Urologic No underlying causes
Miscellaneous No underlying causes

Causes in Alphabetical Order

Symptoms and Signs

Some common symptoms and signs of mastoiditis include pain and tenderness in the mastoid region, as well as swelling. There may be ear pain (otalgia), and the ear or mastoid region may be red (erythematous). Fever or headaches may also be present. Infants usually show nonspecific symptoms, such as anorexia, diarrhea, or irritability. Drainage from the ear occurs in more serious cases.

Prognosis

With prompt treatment, it is possible to cure mastoiditis. Seeking medical care early is important. However, it is difficult for antibiotics to penetrate to the interior of the mastoid process and so it may not be easy to cure the infection; it also may recur. Mastoiditis has many possible complications, all connected to the infection spreading to surrounding structures. Hearing loss may result, or inflammation of the labyrinth of the inner ear (labyrinthitis) may occur, producing vertigo. The infection may also spread to the facial nerve (cranial nerve VII), causing facial-nerve palsy which can produce weakness or paralysis of some facial muscles on that side of the face. Other complications include Bezold's abscess, an abscess (a collection of pus surrounded by inflamed tissue) behind the sternocleidomastoid muscle in the neck, or a subperiosteal abscess, between the periosteum and mastoid bone ( resulting in the typical appearance of a protruding ear). Serious complications result if the infection spreads to the brain. These include meningitis (inflammation of the protective membranes surrounding the brain), epidural abscess (abscess between the skull and outer membrane of the brain), dural venous thrombophlebitis (inflammation of the venous structures of the brain), or brain abscess.

Diagnosis

The diagnosis of mastoiditis is clinical—based on the medical history and physical examination. Imaging studies may provide additional information; the study of choice is the CT scan, which may show focal destruction of the bone or signs of an abscess (a pocket of infection). X-rays are not as useful. If there is drainage, it is often sent for culture, although this will often be negative if the patient has begun taking antibiotics.

Treatment

The primary treatment for acute mastoiditis without osteitis is the administration of intravenous antibiotics after obtaining cultures. The choice of antimicrobial agents is similar to that for acute otitis media—antibiotics against Streptococcus pneumoniae and Haemophilus influenzae. Additional coverage for Staphylococcus aureus and Gram-negative bacilli may be considered for protracted disease until the results of cultures become available.[1][2] Ciprofloxacin (500 mg twice a day) may be considered in immunocompromised patients with diabetes or HIV infection or in infections involving the skin and periauricular areas. Long-term antibiotics may be necessary to completely eradicate the infection. Otalgia associated with otitis externa may be managed with topical anesthesic agent such as benzocaine.

Antibiotic Therapy

Acute Mastoiditis

  • Acute Exacerbation of Chronic Otitis Media

  • Surgery

    If the condition does not respond to antibiotics or is associated with osteitis, surgical procedures may be performed while continuing the medication. The most common procedure is myringotomy with tympanostomy tube placement for drainage and culture of effusion. When an abscess has formed in the mastoid bone, a mastoidectomy should be performed after antimicrobial agents have controlled sepsis.

    Prevention

    In general, mastoiditis is rather simple to prevent. If the patient with an ear infection seeks treatment promptly and receives complete treatment, the antibiotics will usually cure the infection and prevent its spread. For this reason, mastoiditis is rare in developed countries.

    Gallery

    References

    1. Ramakrishnan K, Sparks RA, Berryhill WE (2007). "Diagnosis and treatment of otitis media". Am Fam Physician. 76 (11): 1650–8. PMID 18092706.
    2. Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 978-0-443-06839-3.
    3. http://www.ghorayeb.com
    4. http://www.ghorayeb.com
    5. http://www.ghorayeb.com
    6. http://www.ghorayeb.com
    7. http://www.ghorayeb.com
    8. http://www.ghorayeb.com
    9. http://www.ghorayeb.com

    Further Reading

    • Durand, Marlene & Joseph, Michael. (2001). Infections of the Upper Respiratory Tract. In Eugene Braunwald, Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, Dan L. Longo, & J. Larry Jameson (Eds.), Harrison's Principles of Internal Medicine (15th Edition), p. 191. New York: McGraw-Hill
    • "Mastoiditis" (July 30, 2003). MedlinePlus Medical Encyclopedia.

    Template:Diseases of the ear and mastoid process