Otitis media
Encyclopedia
Otitis media is inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 of the middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...

, or a middle ear infection.

It occurs in the area between the tympanic membrane and the inner ear
Inner ear
The inner ear is the innermost part of the vertebrate ear. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:...

, including a duct known as the eustachian tube
Eustachian tube
The Eustachian tube is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately 35 mm long. It is named after the sixteenth-century anatomist Bartolomeo Eustachi...

. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache, the other being otitis externa
Otitis externa
Otitis externa is an inflammation of the outer ear and ear canal. Along with otitis media, external otitis is one of the two human conditions commonly called "earache". It also occurs in many other species. Inflammation of the skin of the ear canal is the essence of this disorder...

. Diseases other than ear infections can also cause ear pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...

, including cancers of any structure that shares nerve supply with the ear and shingles which can lead to herpes zoster oticus. Though painful, otitis media is not threatening and usually heals on its own within 2–6 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

Acute otitis media (AOM) is most often purely viral and self-limited, as it usually accompanies viral URI (upper respiratory infection
Upper respiratory tract infection
Upper respiratory tract infections are the illnesses caused by an acute infection which involves the upper respiratory tract: nose, sinuses, pharynx or larynx...

). 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. 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 bacterial meningitis
Bacterial meningitis
Bacterial meningitis refers to meningitis that is caused by bacterial infection.-Signs and Symptoms:*Fever*Seizures*Meningismus*Headache*Vomiting*Photophobia*Altered mental status and coma*Anorexia...

.

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
Mastoid process
The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process...

, ringing in ears (tinnitus
Tinnitus
Tinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...

)

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.

Serous

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
Smoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...

, too short a period of breastfeeding
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...

 and greater amounts of time spent in group child care increased the duration of OME in the first two years of life.

Chronic suppurative

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
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...

 becomes acutely infected, pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...

 builds up behind the eardrum
Eardrum
The eardrum, or tympanic membrane, is a thin membrane that separates the external ear from the middle ear in humans and other tetrapods. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone bridges the gap between the eardrum and the other ossicles...

 (tympanic membrane), frequently causing intense pain. It may result in bullous myringitis, which means that the tympanic membrane is blistered and inflamed
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

.

In severe or untreated cases, the tympanic membrane may rupture, allowing the pus
Pus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...

 in the middle ear space to drain into the ear canal
Ear canal
The ear canal , is a tube running from the outer ear to the middle ear. The human ear canal extends from the pinna to the eardrum and is about 35 mm in length and 5 to 10 mm in diameter....

. 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
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

 and the ear drum nearly always heals.

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
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 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
Streptococcus pneumoniae
Streptococcus pneumoniae, or pneumococcus, is Gram-positive, alpha-hemolytic, aerotolerant anaerobic member of the genus Streptococcus. A significant human pathogenic bacterium, S...

. Others include Pseudomonas aeruginosa
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...

, nontypeable Haemophilus influenzae, and Moraxella catarrhalis
Moraxella catarrhalis
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system and joints of humans.-History:...

. Among older adolescents and young adults, the most common cause of ear infections is Haemophilus influenzae
Haemophilus influenzae
Haemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...

. Viruses such as respiratory syncytial virus (RSV) and those that cause the common cold
Common cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...

 may also result in otitis media by damaging the normal defenses of the epithelial cells in the upper respiratory tract
Upper respiratory tract
The upper respiratory tract or upper airway primarily refers to the parts of the respiratory system lying outside of the thorax or above the sternal angle. Another definition commomly used in medicine is the airway above the glottis or vocal cords...

.

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.

Susceptibility is heritable, though the specific genetic markers are still under investigation. Casselbrant et al. found in 2009 that the "best-supported linkage regions may contain susceptibility genes that influence the risk for recurrent/persistent OM. Plausible candidates in 17q12 include AP2B1
AP2B1
AP-2 complex subunit beta is a protein that in humans is encoded by the AP2B1 gene.-Interactions:AP2B1 has been shown to interact with TGF beta receptor 2, AP1M2, BUB1B, LDLRAP1 and Arrestin beta 2.-Further reading:...

, CCL5, and a cluster of other CCL genes, and in 10q22.3, SFTPA2."

Progression

Typically, acute otitis media follows a cold
Common cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...

: 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
Pus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...

 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
Eustachian tube
The Eustachian tube is a tube that links the nasopharynx to the middle ear. It is a part of the middle ear. In adult humans the Eustachian tube is approximately 35 mm long. It is named after the sixteenth-century anatomist Bartolomeo Eustachi...

 swell due to an upper respiratory infection, allergies
Allergy
An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...

, or dysfunction of the tubes. The Eustachian tube remains blocked most of the time. The air present in the middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...

 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
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 behind the tympanic membrane (eardrum) multiply when the conditions are ideal, infecting the middle ear fluid.

Children

Children younger than seven are much more prone to otitis media due to shorter Eustachian tubes, which are at a more 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 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. Breastfeeding for the first twelve months of life is associated with a reduction in the number, and duration of all OM infections.

Pacifier use has been associated with more frequent episodes of AOM.

Diagnosis

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
Otoscope
thumb|right|200px|Otoscope - Image of an otoscope thumb|200px|Anatomy of the human ear.thumb|200px|Right tympanic membrane as seen through a speculum.An Otoscope or auriscope is a medical device which is used to look into the ears...

 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.

Prevention

Pneumococcal conjugate vaccines when given during infancy decrease rates of acute otitis media by 6–7% and if implemented broadly would have a significant public health
Public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...

 benefit. Evidence does not support zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 supplementation as an effort to reduce otitis rates except maybe in those with severe malnutrition
Malnutrition
Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....

 such as marasmus
Marasmus
Marasmus is a form of severe protein-energy malnutrition characterized by energy deficiency.A child with marasmus looks emaciated. Body weight may be reduced to less than 80% of the average weight that corresponds to the height . Marasmus occurrence increases prior to age 1, whereas kwashiorkor...

. Long term antibiotics, while they decrease rates of infection during treatment, have an unknown effect on long term outcomes such as hearing loss. Certain factors such as season, allergy predisposition and presence of older siblings are known to be determinants of recurrent otitis media and persistent middle ear effusions (MEE). Previous history of recurrence, environmental exposure to tobacco smoke, use of daycare, and lack of breastfeeding have all been associated with increased risk of OM development, recurrence, and persistent MEE. Breastfeeding can reduce the rates of OM from 19% to 6% in children that were breastfed for at least one year. Reduction of risk factors in combination with medicinal or surgical methods are necessary to reduce the recurrence of OM and prevent persistent MEE.

Symptomatic

Oral and topical analgesics are effective to treat the pain caused by otitis media. Oral agents include ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....

, paracetamol
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...

(acetaminophen), and narcotics. Topical agents shown to be effective include antipyrine and benzocaine ear drops
Antipyrine and benzocaine ear drops
Antipyrine and benzocaine ear drops is a medication for the treatment of ear pain caused by otitis media. It combines antipyrine, a pain reliever and benzocaine, a numbing agent to treat ear pain...

. Decongestants and antihistamines
Antihistamine
An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...

, either nasal or oral, are not recommended due to the lack of benefit and concerns regarding side effects.

Antibiotics

Deferring the start of antibiotics in acute otitis media for one to three days if pain is manageable with the above measures is currently recommended as: 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 (aged six months to two years) who were treated with amoxicillin
Amoxicillin
Amoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...

.

The first line antibiotic treatment, if warranted, is amoxicillin
Amoxicillin
Amoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...

. If there is resistance
Antibiotic resistance
Antibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a...

, then amoxicillin-clavulanate
Co-amoxiclav
Amoxicillin/clavulanic acid or co-amoxiclav is a combination antibiotic consisting of amoxicillin trihydrate, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor...

 or another penicillin derivative plus beta lactamase inhibitor is second line. While less than 7 days of antibiotics have less side effects more than seven days appear to be more effective. Among short-course antibiotics, long-acting azithromycin
Azithromycin
Azithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...

 was found more likely to be successful than short-acting alternatives.

Tympanostomy tube

In chronic cases with effusions, insertion of tympanostomy tube
Tympanostomy tube
A tympanostomy tube is a small tube inserted into the eardrum in order to keep the middle ear aerated for a prolonged period of time, and to prevent the accumulation of mucus in the middle ear. The operation to insert the tube involves a myringotomy...

 (also called a "grommet") into the eardrum
Eardrum
The eardrum, or tympanic membrane, is a thin membrane that separates the external ear from the middle ear in humans and other tetrapods. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone bridges the gap between the eardrum and the other ossicles...

 reduces recurrence rates in the 6 months after placement but have little effect on long term hearing. Thus tubes are recommended in those who have more than 3 episodes of acute otitis media in 6 month or 4 in a year associated with an effusion.

Alternative therapies

Complementary and alternative medicine is not recommended for otitis media with effusion because there is no evidence of benefit. There is an osteopathic manipulation
Joint manipulation
Joint manipulation is a type of passive movement of a skeletal joint. It is usually aimed at one or more 'target' synovial joints with the aim of achieving a therapeutic effect.- Biomechanics of joint manipulation :...

technique called the Galbreath technique that can be done at home which is intended to improve drainage. The technique was evaluated in one randomized controlled clinical trial; one reviewer concluded that it was promising, but a 2010 evidence report found the evidence inconclusive.

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.

Hearing loss

Children with recurrent episodes of acute otitis media and those suffering from otitis media with effusion or chronic otitis media, have higher risks of developing conductive and sensorineural hearing loss.

This hearing loss is mainly due to fluid in the middle ear or rupture of the tympanic membrane. Prolonged duration of otitis media is associated with ossicular complications, and together with persistent tympanic membrane perforation contributes to the severity of both the disease and the hearing loss. When a cholesteatoma or granulation tissue is present in the middle ear, the degree of hearing loss and ossicular destruction is even greater.

Periods of conductive hearing loss from otitis media may have a detrimental effect on speech development in children. Recent studies have also linked otitis media to educational problems, attention disorders, and problems with social adaptation. Furthermore it has been demonstrated that patients suffering from otitis media have more depression/anxiety-related disorders compared to individuals with normal hearing. Once the infections resolve and hearing thresholds return to normal, childhood otitis media may still cause minor and irreversible damage to the middle ear and cochlea.

Epidemiology

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 Down syndrome (DS) anatomically have more severe curves to their tubes, hence why DS 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.

External links

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