Acute otitis media

Acute otitis media is defined as an infection of the middle ear space. It is a spectrum of diseases that include acute otitis media (AOM), chronic suppurative otitis media (CSOM), and otitis media with effusion (OME). Acute otitis media is the second most common pediatric diagnosis in the emergency department following upper respiratory infections. Although otitis media can occur at any age, it is most commonly seen between the ages of 6 to 36 months

Infection of the middle ear can be viral, bacterial, or coinfection. The most common bacterial organisms causing otitis media are Streptococcus pneumoniae, followed by non-typeable Haemophilus influenzae (NTHi), and Moraxella catarrhalis. Following the introduction of the conjugate pneumococcal vaccines, the pneumococcal organisms have evolved to non-vaccine serotypes. The most common viral pathogens of otitis media include the respiratory syncytial virus (RSV), coronaviruses, influenza viruses, adenoviruses, human metapneumovirus, and picornaviruses.

Otitis media is diagnosed clinically via objective findings on physical exam (otoscopy) combined with the patient's history and presenting signs and symptoms. Several diagnostic tools are available such as a pneumatic otoscope, tympanometry, and acoustic reflectometry to aid in the diagnosis of otitis media. Pneumatic otoscopy is the most reliable and has a higher sensitivity and specificity as compared to plain otoscopy, though tympanometry and other modalities can facilitate diagnosis if pneumatic otoscopy is unavailable.

Treatment of otitis media with antibiotics is controversial and directly related to the subtype of otitis media in question. Without proper treatment, suppurative fluid from the middle ear can extend to the adjacent anatomical locations and result in complications such as tympanic membrane (TM) perforation, mastoiditis, labyrinthitis, petrositis, meningitis, brain abscess, hearing loss, lateral and cavernous sinus thrombosis, and others.[5] This has led to the development of specific guidelines for the treatment of OM.  In the United States, the mainstay of treatment of an established diagnosis of AOM is high dose amoxicillin, and this has been found to be most effective in children under two years of age. Treatment in countries like the Netherlands is initially watchful waiting, and if unresolved, antibiotics are warranted[6]. However, the concept of watchful waiting has not gained full acceptance in the United States and other countries due to the risk of prolonged middle ear fluid and its effect on hearing and speech, as well as the risks of complications discussed earlier. Analgesics such as non-steroidal anti-inflammatory medications such as acetaminophen can be used alone or in combination to achieve effective pain control in patients with otitis media.

The following are the most common symptoms of otitis media. However, each child may experience symptoms differently. Symptoms may include:

Unusual irritability

Difficulty sleeping or staying asleep

Tugging or pulling at one or both ears

Fever, especially in infants and younger children 

Fluid draining from ear(s)

Loss of balance

Hearing difficulties

Ear pain

The symptoms of otitis media may resemble other conditions or medical problems

What causes acute otitis media? The eustachian tube is the tube that runs from the middle of the ear to the back of the throat. An AOM occurs when your child's eustachian tube becomes swollen or blocked and traps fluid in the middle ear. The trapped fluid can become infected.

The eustachian tube is the tube that runs from the middle of the ear to the back of the throat. An AOM occurs when your child’s eustachian tube becomes swollen or blocked and traps fluid in the middle ear. The trapped fluid can become infected. In young children, the eustachian tube is shorter and more horizontal than it is in older children and adults. This makes it more likely to become infected.

The eustachian tube can become swollen or blocked for several reasons:

allergies

a cold

the flu

a sinus infection

infected or enlarged adenoids

cigarette smoke

drinking while laying down (in infants)

The risk factors for AOM include:

being between 6 and 36 months old

using a pacifier

attending daycare

being bottle fed instead of breastfed (in infants)

drinking while laying down (in infants)

being exposed to cigarette smoke

being exposed to high levels of air pollution

experiencing changes in altitude

experiencing changes in climate

being in a cold climate

having had a recent cold, flu, sinus, or ear infection

Genetics also plays a role in increasing your child’s risk of AOM.

The complications of AOM may have become rarer with the advent of antibiotics. A Cochrane review, however, found that antibiotic- and placebo-treated children had similar and very low rates of complications.  

Extracranial complications

Facial Palsy – AOM and a facial palsy without sparing of frontalis. Record the grade of palsy on the House-Brackmann scale, especially commenting on eye closure. This is usually due to a dehiscent facial nerve canal in the middle ear allowing the infection to affect the nerve itself. Patients usually recover well when the infection has resolved.

Mastoiditis – Infection spreading from the middle ear to form an abscess in the mastoid air spaces of the temporal bone. There is a spectrum of disease ranging from AOM through severe AOM to mastoiditis and subperiosteal abscess. Given the number of patients who contract middle ear infections, mastoiditis is relatively rare. Key diagnostic criteria are in bold: 

Tenderness of the mastoid can be normal with uncomplicated ear infections such as otitis externa: mastoiditis patients are systemically very unwell.

Patients with mastoiditis are septic: pyrexial, anorexic and lethargic. Children will be irritable and will not feed. 

Patients will have signs and symptoms of an underlying ear infection eg red, bulging tympanic membrane or purulent ear discharge. 

The sharp angle between the ear and the mastoid, the auriculomastoid sulcus, is lost: compare with the contralateral ear.

As the disease progresses, the pinna is classically pushed downwards and forwards with boggy oedema of the mastoid: compare with the contralateral ear.

Mastoiditis can spread from deep to superficial, forming an abscess beneath the periosteum of the mastoid bone: the swelling typically becomes fluctuant at this stage.

Rarely, such mastoid abscesses can spread inferiorly to the sternomastoid sheath (Bezold's abscess), into the digastric muscle (Citelli's abscess), as well as superomedially to the petrous apex of the temporal bone (petrositis).

Petrositis – Infection spreading to the apex of the petrous temporal bone. There will be sepsis and signs and symptoms of mastoiditis. There is a triad of symptoms known as Gradenigo's Syndrome which entails: purulent otorrhoea, retro-orbital or eye pain (cranial nerve V1 distribution) and ipsilateral lateral rectus palsy (cranial nerve VI).

Intracranial complications

Meningitis – Sepsis, headache, vomiting, neck rigidity, photophobia and positive Kernig’s sign (pain on meningeal stretch eg chin to chest or straight leg raise).

Sigmoid sinus thrombosis – Sepsis, swinging pyrexia and meningitis. If there is distal propagation of the clot then there is a palpable cord in the neck. If there is propagation of the clot to the cavernous sinus, then signs can include proptosis, ophthalmoplegia and chemosis. These patients frequently have another intracranial complication.

Brain abscess – Sepsis with neurological signs. Collections can occur extradurally, subdurally or intracerebrally. Prompt involvement of the neurosurgical team is important.

What can I do to prevent ear infections in myself and my child?

Here are some ways to reduce risk of ear infections in you or your child:

Don’t smoke. Studies have shown that second-hand smoking increases the likelihood of ear infections. Be sure no one smokes in the house or car — especially when children are present — or at your day care facility.

Control allergies. Inflammation and mucus caused by allergic reactions can block the eustachian tube and make ear infections more likely.

Prevent colds. Reduce your child's exposure to colds during the first year of life. Don’t share toys, foods, drinking cups or utensils. Wash your hands frequently. Most ear infections start with a cold. If possible, try to delay the use of large day care centers during the first year.

Breastfeed your baby. Breastfeed your baby during the first 6 to 12 months of life. Antibodies in breast milk reduce the rate of ear infections.

Bottle feed baby in upright angle. If you bottle feed, hold your baby in an upright angle (head higher than stomach). Feeding in the horizontal position can cause formula and other fluids to flow back into the eustachian tubes. Allowing an infant to hold his or her own bottle also can cause milk to drain into the middle ear. Weaning your baby from a bottle between nine and 12 months of age will help stop this problem.

Watch for mouth breathing or snoring. Constant snoring or breathing through the mouth may be caused by large adenoids. These may contribute to ear infections. An exam by an otolaryngologist, and even surgery to remove the adenoids (adenoidectomy), may be necessary.

Get vaccinations. Make sure your child’s immunizations are up to date, including yearly influenza vaccine (flu shot) for those 6 months and older. Ask your doctor about the pneumococcal, meningitis and other vaccines too. Preventing viral infections and other infections help prevent ear infections.