The external ear canal is a tube connecting the outside opening of the ear to the structure called the eardrum. The middle ear is located behind the tympanic membrane and contains three tiny bones called auditory ossicles.   Sound is transmitted via these ossicles to a structure within the inner ear, which delivers it to the brain to be processed.

Otitis media is an infection of the middle ear that is usually caused by bacteria that spreads into the fluid that builds up behind the eardrum. Children are at a higher risk of getting an ear infection than adults. In fact, ear infections are the most common reason why parents bring their child to a doctor as reported by the National Institutes of Health. 18

There are two main types of  otitis media, acute otitis media and otitis media with effusion. Both occur mainly in childhood and both may be caused by bacterial or viral infection.  Acute otitis media is considered the most common ear infection. Parts of the middle ear are infected and swollen leading to fluid entrapment behind the eardrum which blocks the Eustachian tube. The Eustachian tube is a canal connecting the middle ear and the nasopharynx. This causes an earache or pain in the ear. As for otitis media with effusion, it usually follows an episode of acute otitis media where the fluid remains trapped behind the eardrum.

A middle ear infection usually happens because of swelling in one or both of the Eustachian tubes, which lets mucus drain from the middle ear into the throat. A cold, throat infection, acid reflux, or allergies can make the Eustachian tubes swell which blocks the mucus from draining. Following that, viruses or bacteria grow in the mucus to make pus, which builds up in the middle ear causing acute otitis media.

ommon bacterial pathogens causing otitis media are Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Streptococcus pyogenes, while common viruses causing the infection include the respiratory syncytial virus (RSV), rhinoviruses, influenza viruses, and adenoviruses.

The Eustachian tubes are smaller,  more horizontal, and narrower in children than in adults which renders an easy blockage by mucus. The still developing immune system of children makes them more prone to infections and harder to fight  these infections.

Children who have otitis media with effusion are symptomless with the exception of temporary problems with hearing that may be present. Symptoms  accompanying acute otitis media that vary with age include ear pain, sleep disturbances, fever, headache, problems with hearing, and fluid draining from ears.

Most middle ear infections are resolved without problems or long-term effects, but in the case where the fluid is present in the ear for a prolonged period, it can pose a risk of hearing loss. Hearing loss at a young age can interfere with typical speech and language development.

Rare cases of serious complications of otitis media include infection of the bones around the skull called mastoiditis, or the spread of the infection into the meninges, called meningitis.

An otoscope is used by a doctor to examine a suspected middle ear infection. Pneumatic otoscope or a test called tympanometry are used for the fluid in the middle ear inspection. If needed, the doctor will order a hearing test for a patient with persistent ear infections to identify the existence of hearing loss and its degree.

Many middle ear infections  improve on their own, while some ear infections need to be treated with an antibiotic. Several factors are taken into consideration by doctors to determine if antibiotics are needed for an ear infection such as age, illness severity and whether one or both ears are infected. Painkillers such as acetaminophen or ibuprofen can help relieve earache or fever until the antibiotic takes effect.

Many methods are being explored by researchers sponsored by the National Institutes of Health to improve prevention, diagnosis, and treatment of middle ear infections. For example, changing some lifestyle habits, keeping children with the recommended immunizations, breastfeeding for at least 6 months and preventing exposure to secondhand smoke can help protect kids against ear infections.

Acute otitis media shows a usual complete resolution in a few days, except for a few complications. Speech or language delay is uncommon but can occur in a child who has persistent hearing loss from many repeated ear infections.

According to a systematic review and global estimates published in the US journal PLoS One, acute otitis media affects 10.85% of people each year (709 million cases) with 51% of these cases occuring in those below five years.

Otitis media is an infection of the middle ear, the area located exactly behind the eardrum. Fluid may block the Eustachian tubes, which connect the middle ear to the nasopharynx causing otitis media to occur. When mucus, pus, and bacteria accumulate behind the eardrum, they cause pressure and pain, dizziness, and partial loss of hearing. Virus or bacteria are the main causes of otitis media. The start point of ear infections is usually a cold, allergy or upper respiratory infection. Although adults can get ear infections, they are most common in infants and young children due to the Eustachian tubes being smaller, more level, narrower and shorter in children making it easier for the fluid to accumulate.

There are two main types of the otitis media. Both occur mainly in childhood:22,18

1. Acute otitis media

 It is a painful type of ear infection affecting the middle ear, and causing pain and swelling of the eardrum. The blockage of the bottom of the Eustachian tube may result from allergies, colds, respiratory infections, and inflamed or enlarged adenoids leading to the normally produced fluids to build up in the middle ear and in some cases bacteria or viruses can infect the trapped fluid.

1. Otitis media with effusion

 Fluid buildup causes this inflammation but is without bacterial or viral infection or signs and symptoms of an infection which include pain, redness of the eardum, pus and fever. The cause of this is persistent of fluid buildup after an ear infection has been cured. It is considered more common than acute otitis media..21

20,21 Middle ear conditions that may be related to an ear infection or result in similar middle ear problems include the following:

• Chronic suppurative otitis media

 A continuous ear infection that mostly lead to tearing or perforation of the eardrum.

• Chronic otitis media with effusion

This happens when the fluid stays in the middle ear and is recurrent but without bacterial or viral infection which  makes children more vulnerable to new ear infections, and may affect hearing.

• Adhesive otitis media

 The suction of the thin retracted eardrum into the middle ear space makes it stuck which causes adhesive otitis media.

The blockage of the Eustachian tubes leading to the normally produced fluids to build up in the middle ear with a possible involvement of  a virus or bacteria in infecting the trapped fluid causing otitis media. This blockage can be caused by:

• A respiratory infection, such as colds or throat infections.
• Allergy that causes inflammation (swelling) of the nasal passage and upper respiratory tract, which promotes blockage of the Eustachian tube.
• Exposure to cigarette smoke.
• Infected or overgrown adenoids (tonsils).
• A sudden increase in air pressure such as descending in an airplane or on a mountain road.
• For infants, being fed while lying down (drinking a bottle while lying on the back)

Many factors can increase the likelihood of developing otitis media, which includes:

• Age

 Children between ages 6 to 36 months could have recurrent ear infections more than adults because of their shorter, narrower and more horizontal Eustachian tubes that allow bacteria and viruses to find their way into the middle ear more easily and makes them more subjected to be blocked.

• Their adenoids, gland-like structures at the back of the throat, are larger which makes them obstruct the opening of the Eustachian tubes.
• Their poorly developed immune systems makes them more vulnerable to get more colds and respiratory infections than adults, in addition to other factors that include using a pacifier, drinking from a bottle while laying down, and being around other kids in childcare.

• Season

• Ear infections are more common during fall and winter that can make. colds and allergy spread among these seasons more often, keeping in mind that ear infections are not contagious.
• Exposure to air pollution or secondhand smoke.
• The rates of infection are higher in boys than in girls.
• Hereditary factors increase the tendency to get ear infections.

• Colds

The chance of an ear infection often increases by having a cold. Having a history of allergies, like hay fever which is also known as allergic rhinitis or sinusitis increase the possibility of the occurrence of otitis media.

• Having a gastroesophageal reflux disease history.

• Chronic illnesses

Chronic (long-term) illnesses, immune deficiency and chronic respiratory disease, in particular, such as cystic fibrosis and asthma in people makes them at a higher risk of getting ear infections.

• Cleft palate

Cleft palate  is a defect that happens at birth causing a split in the roof of the child’s  mouth.

• Down's syndrome

 A genetic condition that is usually accompanied by a level of learning disability and a characteristic range of physical features.

Pathophysiology of otitis media

Three parts compose the ear an outer, middle, and inner parts. Delicate bones lie within the middle ear, behind the ear membrane which are called auditory ossicles. Movement in the eardrum, and then the ossicles are caused by sound vibrations . The ossicles later on send the sound to a structure within the inner ear, which by its role sends it to the brain for processing.

The nasopharynx is a passageway situated behind the nose and leads the inhaled air into the breathing tubes that go into the lungs. Running between the middle ear and the nasopharynx is the Eustachian tube. This canal is responsible for maintaining  the air pressure in the middle ear equal to that outside which gives the eardrum and ossicles a chance to vibrate appropriately, leading to a normal hearing.

Swelling of the Eustachian tubes is caused by  colds, throat infection, acid reflux, or allergies. This enlargement blocks the mucus from draining, and viruses or bacteria grow in the mucus producing pus, which builds up in the middle ear causing acute otitis media.

Pathogenic bacteria or viruses growth are noticed in cultures of fluid obtained from the middle ear.  The most common bacterial pathogens are Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Streptococcus pyogenes while the most common viruses that cause infections are the respiratory syncytial virus (RSV), rhinoviruses, influenza viruses, and adenoviruses.

 Patients with otitis media with effusion will not appear sick and are with no noticeable symptoms. However, they may face temporary problems, such as hearing loss, tinnitus, vertigo and  earache.

 Symptoms more commonly associated with acute otitis media include:

• Ear pain

 In older children and adults it is obviously seen, but for younger children paying attention to other signs like irritability or a great deal of crying is necessary.

• Loss of appetite

 It is noticed  in young children, especially during bottle feeding. During swallowing, pressure in the middle ear changes causing more pain and less desire to eat.

• Irritability

All sorts of continuous pain may cause irritability in children and adults.

• Poor sleep

Fluid shifting may cause the pain to become worse when the child is lying down.

• Fever

 Ear infections can cause temperatures to rise up to 40° C.

• Drainage from the ear

A leakage of yellow, brown, or white fluid that is not earwax  may mean that the eardrum has ruptured.

• Difficulty hearing

Electrical signals are sent to the brain as sound via the bones of the middle ear that connect to the nerves. The accumulation of fluid behind the eardrums makes these electrical signals move slower through the inner ear bones.

• Headache.

• Doctors perform a physical examination to examine the ear using an otoscope, a small instrument similar to a flashlight, to see the eardrum. A healthy eardrum normally appears pinkish gray in color and is translucent but when infected, the eardrum may be inflamed, swollen or red. In the case of otitis media with effusion, the doctor will find evidence of fluid in the middle ear, but with no signs or symptoms of infection. In the case of chronic suppurative otitis media rare findings of a persistent ear infection by the doctor resulted in tearing or perforation of the eardrum.

• Inspection of the fluid in the middle ear using a pneumatic otoscope, which blows a small amount of air at the eardrum causing the eardrum to move back and forth normally, but in the case of the presence of fluid inside the ear, the eardrum will not move as smoothly..
• Tympanometry which is a useful diagnostic test in measuring the movement of the eardrum. It pushes the eardrum to move by sealing off the ear canal and adjusting air pressure in the canal. These steps allow the process of  measuring the efficiency of the eardrum movement and provides an indirect measure of pressure within the middle ear.
• Acoustic reflectometry test measures the amount of sound emitted from the device that is reflected back from the eardrum.  A normal case would be the absorbance of most of the sound. When fluid is present, the more pressure and the more the reflection of the sound is by the eardrum.
• A hearing test,  performed by an audiologist, is necessary for a patient with recurrent ear infections to help determine the presence of any hearing loss and its degree.

Many middle ear infections will resolve on their own, while some ear infections need to be treated with prescribed antibiotic. Therefore, the doctor will decide the best choice of the following:

1) Observation without antibiotics

Based on age, the illness severity, the options for a follow-up and the possibility of an infection of one or both ears, and after observation the doctor will be able to estimate the duration of symptoms. The usual time for most ear infections to clear up is within three to five days on their own without antibiotic treatment.

2) Antibiotics

According to Centers for Disease Control and Prevention, acute otitis media is on top of the list by which antibiotics are prescribed among common childhood infections. . 17Many doctors will prescribe an antibiotic, such as amoxicillin, for a duration of seven to 10 days to kill the bacteria causing the ear infection.18   Abiding to taking the regular doses and completing the medication’s course will prevent the  ear infection from occurring again, even in the case where the pain and fever are gone. However, in the case of the usage of antibiotics the doctor should be notified about medical history, if there was a case of antibiotic overuse which can lead to antibiotic-resistant bacteria that causes difficulty in treatment later on.

Antibiotics may cause a few side effects such as nausea, diarrhea, rashes, or yeast infections, and with possible interaction with other medications, and rarely, allergic reactions can occur. Fever and pain should disappear within two days of beginning the antibiotics’ treatment, otherwise the doctor should be contacted.

3) Pain relief

Earache or fever are relieved by many types of painkillers until the antibiotic takes effect. Common painkillers are acetaminophen or ibuprofen  that usually control the pain within 1 to 2 hours. Earaches become worse and the pain is increased at bedtime. Painkillers should be age appropriate, especially in children.

4) Restrictions

 Restriction may reduce the possibility for ear infection. Covering the ears when going outside is not necessary. Swimming is permitted with the condition of no perforation or tearing in the eardrum or drainage from the ear exist. The discomfort during air travel can be minimized by swallowing fluids, chewing on gum during descent, or having a child suck on a pacifier. The return of children to school or day care is possible once the fever is gone. The fluid behind the eardrum can be cleared by a few methods which are to avoid cigarette smoke, encourage infants to breastfeed and treat allergies by staying away from triggers.

5) Myringotomy

This is done in the case where fluid remains in the ear for more than 3 months in children, and is usually done under general anesthesia. This procedure includes the insertion of  small metal or plastic tubes through the eardrum to equalize pressure between the middle and outer ear. These tubes will  stay in the body for a duration of six to 12 months to eventually fall out on their own. Complete dryness of the outer ear and with no contact with water is a necessity until the holes have closed completely.

The majority of middle ear infections usually clear up without problems or long-term effects. However, serious complications of middle ear infections are rare, but very young children remain at risk due to their developing immune systems. Some of the main complications associated with middle ear infections are described in detail as follows:

1) Mastoiditis

It is the case when the infection spreads out of the middle ear and into the mastoids. Its treatment includes a usual  administration of antibiotics given through a drip directly into a vein, at the hospital. In some cases, surgery is necessary in order to drain the ear and remove the infected mastoid bone.

2) Cholesteatoma

When middle ear infections are recurrent, an abnormal collection of skin cells inside the ear sometimes develops. This accumulation damages the delicate structures located deep inside the ear, such as the tiny bones that are essential for hearing. Most cases require surgery to remove a cholesteatoma.

3) Labyrinthitis

The spread of the middle ear infection into the delicate structure deep inside the ear called the labyrinth causes this case. Symptoms of labyrinthitis can include dizziness, vertigo which is the feeling that you or the environment around you is moving or spinning, loss of balance and hearing loss.

4) Hearing loss

Temporary hearing problems happen because of fluid buildup in the middle ear that blocks sound as well. Children having this problem might not respond to soft sounds, need to turn up the TV or radio, talk louder and seem inattentive at school. A child with a ruptured eardrum might feel ringing or buzzing in the ear and a may not hear as well as usual.

5) Problems with speech and language development

These problems develop in the case where the child has frequent ear infections that affect their hearing while they are very young making them at a higher risk.

6) Meningitis

The spread of the middle ear infection into the meninges which is the protective outer layer of the brain and spinal cord results in the very rare and serious complication of a middle ear infection called meningitis. Treatment of bacterial meningitis is done in hospital with antibiotics given through a drip directly into a vein.

7) Brain abscess

It is a swelling that is filled by pus and develops inside the brain causing another very rare and serious complication of a middle ear infection. Treatment for brain abscess involves a combination of both antibiotics and surgery.

8) Facial paralysis

This happens when the swelling associated with otitis media can lead to the compression of the facial nerve, in rare cases. The facial nerve is part of a nerve that extends into the skull and is responsible for controlling facial expressions. Compression of the nerve renders a person to be unable to move some or all of their face which is known as facial paralysis. Once the infection is cured, facial paralysis is resolved and rarely causes any long-term problems.

Prevention of ear infections in children and adults can be done using many ways, but usually changing the home’s environment is all that needs to be done. Some of these ways include:

1) Avoiding smoking and exposure to secondhand smoke

In this case, an individual should avoid contact with second-hand tobacco smoke, which is also known as passive smoking. this promotes the increase in the number and severity of ear infections. At home, a person should make sure that no smoking happens, especially in the presence of children.

2) Control allergies

Ear infections may result from inflammation caused by allergies.

3) Breastfeeding

Breast milk contains antibodies that help prevent the development of early episodes of ear infections if the baby is breastfed during the first 6 to 12 months of life. In the case where the baby is bottle-fed, the baby should be held at a 45-degree angle instead of lying the child down with the bottle. The horizontal positioning while feeding can cause formula and other fluids to flow back into the Eustachian tubes.

4) Hygiene

The spread of germs can lead to colds and, therefore, ear infections which makes repeated washing of the hands in the correct way by parents and kids an effective way of prevention.

5) Immunization

Taking the influenza, or flu, vaccine every year should be done upon consulting the child’s doctor. Vaccination should begin at 2 months of age for children under age 2 according to the Centers for Disease Control and Prevention (CDC) recommendations. Based on studies, vaccinated children are less likely to have ear infections than children who are not vaccinated. Vaccination is strongly recommended for children in daycare.

6) Treatment for snoring or breathing through the mouth

Large adenoids that contribute to ear infections could be manifested in mouth breathing or snoring in children. Examination by an otolaryngologist and even surgery to remove the adenoids may be necessary.

7) Control for children in daycare

Sick children should not spend time together or with other healthy children. During the first year of a child’s life, the usage of large day care centers should be delayed since most ear infections start with cold.

Most cases in both adults and children with acute otitis media and with the exception of the few complications given above, a complete resolution in a few days is the usual case.14

The fluid in the ear causes most children to have slight short-term hearing loss during and immediately after an ear infection, and it can remain behind the eardrum for weeks or even months after the infection has cleared. Speech or language delay is uncommon. However, it may occur in a child who has persistent hearing loss from many repeated ear infections.10

A systematic review and global estimates published in the US journal PLoS One, shows that acute otitis media affects 10.85% of people each year (709 million cases) with 51% of these cases occurring in children less than five years old. Chronic suppurative otitis media occurs at a rate of 4.76‰ (31 million cases) with 22.6% of cases occurring annually in under-fives. The same review reveals that each year 21 thousand people die due to complications of OM.

According to Centers for Disease Control and Prevention, acute otitis media is the most common childhood infection for which antibiotics are prescribed.