Ear Infections (Acute Otitis Media) and Middle Ear Fluid (Otitis Media with Effusion)

How does the ear work?

There are three main parts to the ear: outer, middle and inner. The outer ear (auricle and external auditory canal) is responsible for collecting sound. The middle ear (an air filled cavity separated from the outer ear by the eardrum) contains three tiny bones that vibrate and amplify the sound transmitted to the inner ear. The inner ear converts vibrations into electrical signals and sends these signals to the brain. The inner ear also has a component that helps with balance.

A healthy middle ear contains air at the same pressure as is outside the ear allowing free vibration of the eardrum. Air enters the middle ear through a structure called the eustachian tube that connects the back of the nose to the middle ear. This process of air equalization occurs constantly with chewing and swallowing without our awareness. An example of our feeling this equalization is when the ears pop during an air flight.

Why does my child get ear infections?

In children, the eustachian tube (E.T.) is shorter and more horizontal than in adults. These factors result in poorer E.T. function and may lead to a build up of negative pressure in the middle ear.

In addition, children tend to get more respiratory infections.  With these infections, the eustachian tubes become inflamed and bacteria can easily travel from the throat to the middle ear and lead to infection.  The infection is known as acute otitis media.  As bacteria multiply in the middle ear, pus develops behind the eardrum and pain and fever develop.  These infections are usually treated with oral antibiotics.  Other conditions such as allergies, sinus disease, and even stomach acid reflux can cause irritation to the tissue around the eustachian tube that results in inflammation. Enlargement or infection of the adenoids, which are located behind the nose, provide a source for bacteria and in some cases block the opening to the eustachian tube. All of these problems can cause frequent ear infections. Many of these issues improve when the child turns 5-6 years old.

What is an effusion?

Often after the symptoms of acute otitis media clear up, fluid remains in the middle ear, which is called a middle ear effusion. This fluid may take up to three months or longer to clear. This condition is not considered an infection. Persistent fluid in the ear does not need to be treated with antibiotics. Children may experience hearing loss, a pressure sensation or no symptoms at all. The treatment is to recheck the ears to ensure that the fluid has resolved.

What are the risk factors for developing ear infections?

The development of an ear infection can be due to many things. Some of these factors can be modified to help prevent ear infections.

• Daycare: Colds often lead to ear infections. Children in group-childcare settings have a higher chance of passing their colds to each other because they are exposed to more germs and viruses from the other children. If your child has recurrent ear infections, he/she may benefit from a change to a smaller daycare setting or a removal from daycare.
• Eustachian tube dysfunction/obstruction: This may result from allergies and enlarged or infected adenoids.
• Tobacco Smoke: Children who are exposed to second hand smoke experience a higher risk of developing health problems, including ear infections.
• Bottle-feeding: Babies who are bottle fed, especially while lying down, have a tendency to experience more infections then breastfed babies. If you bottle feed your child, hold his or her head above the stomach level during feedings.
• Age: Infants and young children are more likely to get ear infections. The highest incidence is in children between 6 and 18 months.
• Genetic Issues: Children with problems such as cleft palate and Down Syndrome have underlying abnormalities that affect eustachian tube function.
• Inheritance: Children with parents and siblings with a history of ear infections have a higher incidence.

What treatments are available?
 
In most cases, middle ear fluid will clear naturally over time. If no other symptoms are present (runny nose, etc.), oral decongestants do not help. Intranasal corticosteroid sprays are sometimes used to help the fluid clear. If your child has an ear infection (acute otitis media), then antibiotics will be prescribed. Your child may need 2 or more separate courses to treat the infection. For recurrent ear infections (4 episodes in 6 months) or persistent middle ear fluid for more than 3-4 months with hearing loss, your child may benefit from tympanostomy tubes. If allergies are contributing to ear infections, an allergy evaluation and/or antihistamine medications and corticosteroid sprays may benefit your child. If your child is also snoring and mouth breathing, the adenoids may be obstructing the area around the opening to the eustachian tube. There are different methods to treat this condition depending on the specific circumstances of each child.

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