Otitis media
From Wikipedia, the free encyclopedia
| ICD-10 | H65-H67 |
|---|---|
| ICD-9 | 381-382 |
| eMedicine | EMERG/351 |
Otitis media is an inflammation of the middle ear segment of the ear. It is one of the two conditions that are commonly thought of as ear infections, the other being otitis externa. Otitis media is very common, and includes a whole range of medical conditions; all of which involve inflammation of the ear drum (tympanic membrane), and are usually associated with a buildup of fluid in the space behind the ear drum (middle ear space).
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[edit] Types
There are several kinds of otitis media:
- Acute otitis media is an infection that produces pus, fluid, and inflammation within the middle ear. It is frequently associated with signs of upper respiratory infection, such as a runny nose or stuffy nose. It is often associated with Mastoiditis.
- Otitis media with effusion, formerly termed serous Otitis Media or secretory Otitis Media, is Middle Ear Effusion of any duration that lacks the associated signs and symptoms of infection (eg, fever, otalgia, irritability). Otitis Media with Effusion usually follows an episode of Acute Otitis Media.
- Chronic otitis media may develop when the infection persists for more than two weeks.
- Adhesive Otitis Media, commonly referred to as Glue Ear.
[edit] Progression
The typical progress of otitis media is: the tissues surrounding the Eustachian tube swell due to an infection and/or severe congestion. The Eustachian tube remains blocked most of the time. The air present in the middle ear is slowly absorbed into the surrounding tissues. A strong negative pressure creates a vacuum in the middle ear. The vacuum reaches a point where fluid from the surrounding tissues accumulates in the middle ear. This is seen as a progression from a Type A tympanogram, to a Type C, to a Type B tympanogram. The fluid may become infected. It has been found that dormant bacteria behind the Tympanum (eardrum) multiply when the conditions are ideal infecting the middle ear fluid.
[edit] Otorrhea: Infected Drainage from the Middle Ear
When the middle ear becomes acutely infected, pressure builds up behind the ear drum and, in severe cases, the tympanic membrane may rupture. Once perforated, the pus drains out into the ear canal. If there is enough of it, this drainage may be obvious. Even though the rupture of the tympanic membrane suggests a dramatic and traumatic process, the opening may or may not be painful, and can be associated with the dramatic relief of pressure and pain. In a simple case of acute otitis media in an otherwise healthy person, the body's defenses are likely to resolve the infection and the ear drum nearly always heals up again.
Instead of resolution of the infection, however, drainage from the middle ear can become a chronic condition. The World Health Organization defines CSOM as 'a stage of ear disease in which there is chronic infection of the middle ear cleft, a non-intact tympanic membrane (i.e. perforated eardrum) and discharge (otorrhoea), for at least the preceding two weeks' (WHO 1998)
[edit] Causes
Streptococcus pneumoniae and Haemophilus influenzae are the most common bacterial causes of otitis media. Tubal dysfunction leads to the ineffective clearing of bacteria from the middle ear.
As well as being caused by Streptococcus pneumoniae and Haemophilus influenzae it can also be caused by the common cold.
Another common culprit of otitis media includes Moraxella catarrhalis, a gram-negative, aerobic, oxidase positive diplococcus.
[edit] Susceptibility in children
Children below the age of seven years are much more prone to otitis media since the Eustachian tube is shorter and at more of a horizontal angle than in the adult ear. They also have not developed the same resistance to viruses and bacteria as adults. There is also an association with maternal smoking habits.[1]
[edit] Treatment
Whilst antibiotics were previously routinely immediately started, there is poor evidence as to their efficacy at shortening disease duration compared to the illness's natural history in the majority of children.[2][3]
Protocols now exist for deferring the start of antibiotics for up to 72 hours.[4] This results in 2 out of 3 children avoiding the need to start antibiotics,[5] and no adverse effect on longterm outcomes for those whose treatment is deferred.[6]
In chronic cases or with effusions present, surgery is sometimes performed to insert a grommet (called a "tympanostomy tube") into the eardrum to allow air to pass through into the middle ear, and thus release any pressure buildup and help clear excess fluid within.
Along with medical treatment it is possible to use the Valsalva maneuver to reestablish middle ear ventilation. Please note, however, that repeated use of the Valsalva maneuver to dislodge infected matter from the middle ear can cause this matter to enter the eye cavity, leading to conjunctivitis.
[edit] Footnotes
- ^ Ilicali O, Keleş N, Değer K, Savaş I (1999). "Relationship of passive cigarette smoking to otitis media.". Arch Otolaryngol Head Neck Surg 125 (7): 758-62. PMID 10406313.
- ^ Damoiseaux R, van Balen F, Hoes A, Verheij T, de Melker R (2000). "Primary care based randomised, double blind trial of amoxicillin versus placebo for acute otitis media in children aged under 2 years.". BMJ 320 (7231): 350-4. PMID 10657332.
- ^ Arroll B (2005). "Antibiotics for upper respiratory tract infections: an overview of Cochrane reviews.". Respir Med 99 (3): 255-61. PMID 15733498.
- ^ Damoiseaux R (2005). "Antibiotic treatment for acute otitis media: time to think again.". CMAJ 172 (5): 657-8. PMID 15738492.
- ^ Marchetti F, Ronfani L, Nibali S, Tamburlini G (2005). "Delayed prescription may reduce the use of antibiotics for acute otitis media: a prospective observational study in primary care.". Arch Pediatr Adolesc Med 159 (7): 679-84. PMID 15997003.
- ^ Little P, Moore M, Warner G, Dunleavy J, Williamson I (2006). "Longer term outcomes from a randomised trial of prescribing strategies in otitis media.". Br J Gen Pract 56 (524): 176-82. PMID 16536957.
[edit] External links
- What is otitis media?
- Ear Infection - It usually begins with a cold, which can cause fluid to form behind the eardrum.
- Acute otitis media in children
- NIH
- Department of Otolaryngology Health-Related Library (May 19, 1997). Serous Otitis Media. University of Minnesota.
