View source for Mastoiditis

{{Infobox_Disease
 | Name           = Mastoiditis
 | Image          = Gray1193.png 
 | Caption        = Side view of head, showing surface relations of bones. (Mastoid process labeled near center.)  
 | DiseasesDB     = 22479
 | ICD10          = {{ICD10|H|70||h|65}}
 | ICD9           = {{ICD9|383.0}}-{{ICD9|383.1}}
 | ICDO           =
 | OMIM           =
 | MedlinePlus    = 001034
 | eMedicineSubj  = emerg
 | eMedicineTopic = 306
 | eMedicine_mult = {{eMedicine2|ped|1379}}
 | MeshID         = D008417
}}
'''Mastoiditis''' is an infection of [[mastoid process]], the portion of the [[temporal bone]] of the [[skull]] that is behind the [[ear]] which contains open, air-containing spaces.<ref name="nih">{{cite web|url=http://www.nlm.nih.gov/medlineplus/ency/article/001034.htm |title=Mastoiditis |accessdate=July 30, 2003 |publisher=MedlinePlus Medical Encyclopedia}}</ref><ref name="earinfections">{{cite web|url=http://www.webmd.com/cold-and-flu/ear-infection/ear-infections-treatment-overview |publisher=webmd.com |title= Ear Infections - Treatment |accessdate=24 November 2008}}</ref> 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 [[antibiotic]]s, however, mastoiditis has become quite rare in developed countries. It is treated with medications and/or surgery.<ref name="nih" /> If untreated, the infection can spread to surrounding structures, including the [[brain]], causing serious complications.<ref name="emedicine">{{cite web|author=Young, Tesfa |accessdate=June 10, 2005 |url=http://www.emedicine.com/emerg/topic306.htm |title=Mastoiditis |publisher=eMedicine}}</ref>

==Features==
Some common [[symptoms]] and [[Medical sign|signs]] of mastoiditis include [[pain]], tenderness, and swelling in the mastoid region. 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]], including [[anorexia (symptom)|anorexia]], [[diarrhea]], or [[irritability]]. Drainage from the ear occurs in more serious cases.<ref name="whattodo">{{cite web|url=http://www.webmd.com/news/20010502/what-to-do-about-ear-infections |title= What to Do About Ear infections |publisher=webmd.com |accessdate=24 November 2008}}</ref><ref name="emedicine" />

==Diagnosis==
The diagnosis of mastoiditis is clinical&mdash;based on the [[medical history]] and [[physical examination]]. Imaging studies may provide additional information; The standard method of diagnosis is via [[MRI scan]] although a [[CT scan]] is a common alternative as it gives a clearer and more useful image. Planar (2-D) [[X-rays]] are not as useful. If there is drainage, it is often sent for [[microbiological culture|culture]], although this will often be negative if the patient has begun taking antibiotics. Exploratory surgery is often used as a last resort method of diagnosis.<ref name="nih" />

==Pathophysiology==
The pathophysiology of mastoiditis is straightforward: bacteria spread from the middle ear to the [[mastoid air cell]]s, where the inflammation causes damage to the bony structures. The bacteria most commonly observed to cause mastoiditis are ''[[Streptococcus pneumoniae]]'',  and [[gram-negative]] [[bacilli]] such as Pseudomonas aeruginosa and ''[[Haemophilus influenzae]]'',. Other bacteria include ''[[Moraxella catarrhalis]]'', 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.<ref name="emedicine" />

==Prevention and treatment==
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.<ref name="whattodo" />

In the United States the primary treatment for mastoiditis is administration of [[intravenous]] antibiotics. Initially, broad-spectrum antibiotics are given, such as [[ceftriaxone]]. As culture results become available, treatment can be switched to more specific antibiotics. Long-term antibiotics may be necessary to completely eradicate the infection.<ref name="emedicine" /> If the condition does not quickly improve with antibiotics, surgical procedures may be performed (while continuing the medication). The most common procedure is a [[myringotomy]], a small incision in the [[tympanic membrane]] (eardrum), or the insertion of a [[tympanostomy tube]] into the eardrum. These serve to drain the pus from the middle ear, helping to treat the infection. The tube is extruded spontaneously after a few weeks to months, and the incision heals naturally. If there are complications, or the mastoiditis does not respond to the above treatments, it may be necessary to perform a mastoidectomy; a procedure in which a portion of the bone is removed and the infection drained.<ref name="emedicine" />

==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 (inner ear)|labyrinth]] of the [[inner ear]] ([[labyrinthitis]]) may occur, producing [[Vertigo (medical)|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 [[vein|venous]] structures of the brain), or [[brain abscess]].<ref name="nih" /><ref name="emedicine" />

==Epidemiology==
In the [[United States]] and other developed countries, the [[incidence (epidemiology)|incidence]] of mastoiditis is quite low, around 0.004%, although it is higher in developing countries. The most common ages affected are 6&ndash;13 months, as it is during that age that ear infections are most common. Males and females are equally affected.<ref name="earinfections" />

==References==
{{reflist}}

==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
*Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head & Neck Surgery. 4th ed. St Louis, Mo; Mosby; 2005:3019-3020.

{{Diseases of the ear and mastoid process}}
{{Inflammation}}

[[Category:Inflammations]]
[[Category:Otology]]
[[Category:Skeletal disorders]]

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