Otitis media

Otitis media
Classification and external resources
File:Otitis media incipient.jpg Otitis media acuta
ICD-10	H65.-H67.
ICD-9	381-382
DiseasesDB	29620 serous, 9406 suppurative
MedlinePlus	000638 acute, 007010 with effusion, 000619 chronic
eMedicine	emerg/351 ent/426 complications, ent/209 with effusion, ent/212 Medical treat., ent/211 Surgical treat. ped/1689
MeSH	D010033

Otitis media (Latin for "Inflammation of the Middle Ear") is inflammation of the middle ear, or middle ear infection.

Otitis media occurs in the area between the tympanic membrane (the end of the outer ear) and the inner ear, including a duct known as the eustachian tube. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache, the other being otitis externa. Diseases other than ear infections can also cause ear pain, including cancers of any structure that shares nerve supply with the ear and shingles which can lead to herpes zoster oticus. Though severely painful, otitis media is not threatening and usually heals on its own within 2–4 weeks.

Classification

Otitis media has many degrees of severity, and various names are used to describe each. The terminology is sometimes confusing because of multiple terms being used to describe the same condition. A common misconception with ear infection is that sufferers think that a symptom is itchy ear. Although sufferers may feel discomfort, an itchy ear is not a symptom of ear infection.

Acute otitis media

Acute otitis media (AOM) is most often purely viral and self-limited, as is its usual accompanying viral URI (upper respiratory infection). There is congestion of the ears and perhaps mild discomfort and popping, but the symptoms resolve with the underlying URI. If the middle ear, which is normally sterile, becomes contaminated with bacteria, pus and pressure in the middle ear can result, and this is called acute bacterial otitis media. Viral acute otitis media can lead to bacterial otitis media in a very short time, especially in children, but it usually does not. The individual with bacterial acute otitis media has the classic "earache", pain that is more severe and continuous and is often accompanied by fever of 102 °F (39 °C) or more.[citation needed]. Bacterial cases may result in perforation of the ear drum, infection of the mastoid space (mastoiditis) and in very rare cases further spread to cause meningitis.

Features: 1st phase - exudative inflammation lasting 1–2 days, fever, rigors, meningism (occasionally in children), severe pain (worse at night), muffled noise in ear, deafness, sensitive mastoid process, ringing in ears (tinnitus)

2nd phase - resistance and demarcation lasting 3–8 days. Pus and middle ear exudate discharge spontaneously and afterwards pain and fever begin to decrease. This phase can be shortened with topical therapy.

3rd phase - healing phase lasting 2–4 weeks. Aural discharge dries up and hearing becomes normal.

Otitis media with effusion

Otitis media with effusion (OME), also called serous or secretory otitis media (SOM), is simply a collection of fluid that occurs within the middle ear space as a result of the negative pressure produced by altered Eustachian ?tube function. This can occur purely from a viral URI, with no pain or bacterial infection, or it can precede and/or follow acute bacterial otitis media. Fluid in the middle ear sometimes causes conductive hearing impairment, but only when it interferes with the normal vibration of the eardrum by sound waves. Over weeks and months, middle ear fluid can become very thick and glue-like (thus the name glue ear), which increases the likelihood of its causing conductive hearing impairment. Early-onset OME is associated with feeding while lying down and early entry into group child care, while parental smoking, too short a period of breastfeeding and greater amounts of time spent in group child care increased the duration of OME in the first two years of life.

Chronic suppurative otitis media

Chronic suppurative otitis media involves a perforation (hole) in the tympanic membrane and active bacterial infection within the middle ear space for several weeks or more. There may be enough pus that it drains to the outside of the ear (otorrhea), or the purulence may be minimal enough to only be seen on examination using a binocular microscope. This disease is much more common in persons with poor Eustachian tube function. Hearing impairment often accompanies this disease.

Signs and symptoms

When the middle ear becomes acutely infected, pressure builds up behind the eardrum (tympanic membrane), frequently causing intense pain. It may result in bullous myringitis, in which the tympanic membrane is inflamed and blistered.

In severe or untreated cases, the tympanic membrane may rupture, allowing the pus in the middle ear space to drain 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 traumatic process, it is almost always 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. Antibiotic administration can prevent perforation of the eardrum and hasten recovery of the ear.

Instead of the infection and eardrum perforation resolving, however, drainage from the middle ear can become a chronic condition. As long as there is active middle ear infection, the eardrum will not heal. The World Health Organization defines chronic suppurative otitis media (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). (Notice WHO's use of the term serous to denote a bacterial process, whereas the same term is generally used by ear physicians in the United States to denote simple fluid collection within the middle ear behind an intact eardrum. Chronic otitis media is the term used by most ear physicians worldwide to describe a chronically infected middle ear with eardrum perforation.)

Causes

Otitis media is most commonly caused by infection with viral, bacterial, or fungal pathogens. The most common bacterial pathogen is Streptococcus pneumoniae. Others include Pseudomonas aeruginosa, nontypeable Haemophilus influenzae, and Moraxella catarrhalis. Among older adolescents and young adults, the most common cause of ear infections is Haemophilus influenzae. Viruses such as respiratory syncytial virus (RSV) and those that cause the common cold may also result in otitis media by damaging the normal defenses of the epithelial cells in the upper respiratory tract.

A major risk factor for developing otitis media is Eustachian tube dysfunction, which leads to the ineffective clearing of bacteria from the middle ear.

The role of the anti-H. influenzae vaccine that children are regularly given is to prevent invasive disease such as meningitis and pneumonia. This vaccine is active only against strains of serotype b, which has been found to cause meningitis and pneumonia in children under five years, with children between 4 and 18 months the most susceptible. Isolates of serotype b rarely cause otitis media.

Progression

Typically, acute otitis media follows a cold: after a few days of a stuffy nose the ear becomes involved and can cause severe pain. The pain will usually settle within a day or two, but can last over a week. Sometimes the ear drum ruptures, discharging pus from the ear, but the ruptured drum will usually heal rapidly.

At an anatomic level, the typical progression of acute otitis media occurs as follows: the tissues surrounding the Eustachian tube swell due to an upper respiratory infection, allergies, or dysfunction of the tubes. 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, and eventually 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 tympanic membrane (eardrum) multiply when the conditions are ideal, infecting the middle ear fluid.

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. Numerous studies have correlated the incidence of acute otitis media in children with various factors such as nursing in infancy, bottle feeding when supine, parental smoking, diet, allergies, and automobile emissions; but the most obvious weakness of such studies is the inability to control the variable of exposure to viral agents during the studies. One must also keep in mind that correlation does not establish causation. Breastfeeding for the first twelve months of life is associated with a reduction in the number, and duration of all OM infections.

Well pacifier use is associated with more frequent episodes of AOM.

Diagnosis

File:Otitis media schollig.jpg

The tympanic membrane (eardrum) as it appears in someone with acute otitis media

Acute otitis media is usually diagnosed via visualization of the tympanic membrane in combination with the appropriate clinical history. The use of a monocular otoscope and perhaps a tympanometer may not be able to distinguish bacterial versus viral etiology, especially if the canal is small and there is wax in the ear that obscures a clear view of the eardrum. Also, an upset child's crying can cause the eardrum to look inflamed due to distension of the small blood vessels on it, mimicking the redness associated with otitis media.

The occurrence, duration, or severity of symptoms is not predictive of an ear infection in the absence of examination of the eardrum.

Treatment

Pain

To treat the pain caused by otitis media oral as well as topical analgesics are effective. Oral agents may include ibuprofen, acetaminophen, or narcotics. Topical agents shown to be effective include antipyrine and benzocaine ear drops.

Antibiotics

Many guidelines suggest deferring the start of antibiotics in acute bacterial otitis media for one to three days if pain is manageable with the above measures. This is recommended for a number of reasons including: two out of three children with acute otitis media resolve without antibiotic treatment, no adverse effect on long term outcomes have been found when treatment is withheld, antibiotics have significant rates of potential side effects, and a recent trial has found increased rates of recurrence of otitis in children who were treated with antibiotics.

The first line antibiotic treatment, if warranted, is amoxicillin. If the bacteria is resistant, then amoxicillin-clavulanate or another penicillin derivative plus beta lactamase inhibitor is second line. Five days of treatment has been found to be as effective as ten days in otherwise healthy children.

Studies show that of the 10 million annual antibiotic prescriptions for ear infections, somewhere between 8.5 million and 9.5 million prescriptions didn’t help. Roughly 80% of ear infections will clear up without antibiotics. The same study shows in 5 to 14 percent of children, the antibiotics will take one day off the length of the ear infection. While 5 to 14 percent are helped, up to 15 percent of children who take antibiotics will develop diarrhea and up to 5 percent will have allergic reactions, some of which may be quite serious. This has led some to question the therapeutic value of antibiotics in the treatment of this disease. Ear specialists tend to disagree with this philosophy however, and promote efforts to distinguish between viral and bacterial infection, so as to optimize treatment results by giving antibiotics only for bacterial infection. On the other hand, it is generally agreed that acute otitis media that is purely viral will usually resolve without antibiotic treatment, although associated persistent middle ear effusions may require medical intervention.

Azithromycin has been shown to be as effective in treatment of AOM as amoxicillin. Cases were resolved in 80% of children less than two years of age. Treatment with azithromycin also showed greater patient compliance compared with amoxicillin, as well as being associated with less occurrence of diarrhea.

Chronic cases or with effusion

In chronic cases or with effusions present for months, surgery is sometimes performed by an otolaryngologist or by an otologist, to insert a tympanostomy tube (also called a "grommet") 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.

Alternative therapies

There are claims that a variety of unproven techniques provide benefit to otitis media, including local application of iodine, osteopathic and chiropractic manipulation, dietary exclusions, herbal supplements, acupuncture, traditional Chinese medicine, and homeopathy. The efficacy of these alternative therapies has yet to be evaluated with randomised controlled trials with adequate sample sizes. None exist for otitis media.

One small clinical trial investigated the osteopathic Galbreath technique for improving drainage, which it found promising. The technique was described in a 2000 article. A 2006 review of 346 patients found no complications with pediatric osteopathic treatments.

Prognosis

Acute bacterial otitis media can cause pain that leads to sleepless nights for both children and parents, can cause eardrum perforations, not all of which heal, and can spread to cause mastoiditis and/or meningitis, brain abscess, and even death if a severe infection goes untreated long enough. High fever can occur and can cause febrile seizures. Appropriate antibiotic administration prevents most such complications.

Epidemiology

File:Otitis media world map - DALY - WHO2002.svg

Disability-adjusted life year for otitis media per 100,000 inhabitants in 2002.

     no data      less than 10      10-14      14-18      18-22      22-26      26-30      30-34      34-38      38-42      42-46      46-50      more than 50

Otitis media is very common in childhood, with the average toddler having two to three episodes a year, almost always accompanied by a viral upper respiratory infection (URI), mostly the common cold. The rhinoviruses (nose viruses) that cause the common cold infect the Eustachian tube that goes from the back of the nose to the middle ear, causing swelling and compromise of pressure equalization, which is one of the normal functions of the tube. The other main function is the lateral drainage of fluids from tissues on either side of the skull. It has to be remembered that the Eustachian Tube is only the width of three to four hairs in places along its length. It also changes its anatomical and physiological appearance during the early growth period of the child. In the newborn the tube is horizontal making it more difficult to drain naturally, and the surface of the tube is 100% cartilage, with a lining of Lymphatic tissue which is an extension of the Adenoidal tissue from the back of the nose. As the early years pass by the superior (upper) part of the tube ossifies to bone but the lower remains the same. The angle of the tubes changes and descends to roughly a 45 degree angle increasing the downward flow of fluids. It should be noted that individuals with Downs Syndrome anatomically have more severe curves to their tubes, hence why D.S children tend to have more grommet operations than other children. In general, the more severe and prolonged the compromise of Eustachian tube function, the more severe the consequences are to the middle ear and its delicate structures. If a person is born with poor Eustachian tube function, this greatly increases the likelihood of more frequent and severe episodes of otitis media. Progression to chronic otitis media is much more common in this group of people, who often have a family history of middle ear disease.

History

Prior to the invention of antibiotics, severe acute otits media was mainly remedied surgically by myringotomy. An outpatient procedure, it consists of making a small incision in the tympanic membrane to relieve pressure build-up.

Gallery

• Otitis media bullös.jpg

  Otitis media acuta - Myringitis bullosa

• Otitis media entdifferenziert2.jpg
• Otitis media grippe.jpg

  Influenza

• Otitis media schollig.jpg

  Otitis media acuta

• Otitis chron mesotymp 7.jpg

  Otitis media chronica mesotympanalis

• Otitis chron mesotymp 4.jpg

  Otitis media chronica mesotympanalis

• Otitis chron mesotymp 3.jpg

  Otitis media chronica mesotympanalis

• Otitis chron mesotymp 1.jpg

  Otitis media chronica mesotympanalis

External links

• Specialist Library for ENT and Audiology High quality research and patient information on otitis media
• AAFP guidelines
• Treatment for ear infection
• Fluid in the Middle Ear: A Guide for Parents, from the Pennsylvania Medical Society, 2009.
• Anatomy of an Ear Infection Pictures Slideshow from MedicineNet

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