Otitis Media

Topic Highlights

' Otitis media is an infection or inflammation of the middle ear which occurs when infections of the throat, nose or respiratory tract spread to the middle ear.

' This visual presentation discusses the anatomy and functions of the ear, causes and risk factors of otitis media, its diagnosis including audiometric analysis, and treatment options.

Transcript

Otitis Media, an infection of the middle ear, is one of the most commonly diagnosed childhood illnesses. After the common cold it is the most common health problem affecting preschool children. Most children have had at least one ear infection by the time they are three. Although otitis media is primarily a disease of infants and young children, it can also affect adults. Every year millions of school days and work days are lost due to otitis media. The condition may lead to serious complications if it is not treated.

The ear is responsible for hearing and balance. The ear consists of three parts - the outer ear, the middle ear, and the inner ear. Sound waves travel through the air and reach the outer ear, or pinna, the visible part of the ear. From the pinna they enter the ear canal and then the middle ear including the eardrum, a thin layer of tissue and the ossicles, which are three tiny bones.

When the sound waves enter, the eardrum vibrates and the ossicles amplify these vibrations and carry them to the inner ear. The inner ear converts the vibrations into electric signals, which are picked up by the auditory nerve. The auditory nerve sends impulses to the brain. The brain interprets the signals as sound.'

When a child develops a cold or an allergy that affects the nasal passages, the eustachian tube may become blocked by inflammation of its lining or due to mucus inside the tube. This blockage will result in the accumulation of fluid within the normally air-filled middle ear resulting in otitis media. Bacteria or viruses that enter the middle ear through the eustachian tube may get trapped in the fluid eventually leading to an ear infection.

Acute otitis media is characterized by infection in the middle ear. The infection occurs suddenly, causing swelling and redness. Fluid and mucus become trapped inside the ear, causing fever and ear pain. The child may experience difficulty in hearing. In otitis media with effusion, the fluid and mucus continue to collect in the middle ear even after the initial infection subsides. The child may experience a feeling of fullness in the ear and loss of hearing.

Symptoms of otitis media include irritability, difficulty in sleeping, fever, discharge from the ear, loss of balance, hearing difficulties, pain in the ear, nausea and vomiting, diarrhea, loss of appetite and congestion. Small children may pull at their ears.

Otitis media can occur as a result of a cold, sore throat, or respiratory infection. A cold or allergy can lead to swelling and congestion of the lining of the nose, throat, and eustachian tube. This swelling prevents the normal flow of fluids.

Children are more susceptible to otitis media than adults as their eustachian tubes are shorter and more horizontal than those of adults. This allows easy access to bacteria and viruses into the middle ear. Eustachian tubes are narrower and less stiff in children making them more prone to blockage.

The adenoids, which are gland-like structures located in the back of the upper throat near the eustachian tubes, are large in children. Enlarged adenoids may block the opening of the eustachian tubes. Tonsillitis also may cause otitis media. Children do not have fully developed immune systems until the age of seven. Thus they are more prone to infections.

Risk factors include secondhand smoke, family history of ear infections, lack of breastfeeding, infections such as common cold and bottle feeding of babies with the baby lying on its back.

Otitis media is diagnosed by the presence of fluid and inflammation of the eardrum. The doctor uses an otoscope to examine the eardrum. The outer part of the ear is gently pulled upwards and backwards. This helps straighten the external auditory canal, which is curved, making it easier to see the eardrum. Otoscope may show dullness, air bubbles, or fluid behind the eardrum.

If there is purulent discharge from the ear, a swab is taken and culture and drug sensitivity is carried out. Tuning fork tests and audiometric analysis is a must for all cases. If complications are present then a CT scan is vital. An MRI scan and a radio isotope studying would be ideal. In the case of long standing infections, a biopsy should be done to rule out malignancy.

Treatment is based on symptoms and severity of infection. Antibiotics may be prescribed for bacterial infection. Eardrops are prescribed if there is a hole in the eardrum. Decongestive nasal drops are administered to increase nasal drainage and relieve stuffiness.

Surgical removal of the adenoids may be necessary to allow the eustachian tube to open. Myringotomy or surgical opening of the eardrum may be required to drain the fluid. Sometimes, drainage tubes may be placed in the ear. Tympanostomy tube insertion is done under general anesthesia. In this procedure, a tiny tube is inserted into the eardrum, to allow for a small opening for air to get in, so fluids can drain more easily down the eustachian tube. The tube will usually fall out in its own. Ears should be kept clean and dry to prevent reinfection.

Prompt antibiotic treatment reduces complications of otitis media. Untreated otitis media may result in the infection spreading to other parts of the head. Permanent hearing loss may occur. In small children, loss of hearing may impair speech and language development. Other serious complications include meningitis, facial palsy, mastoiditis, and brain abscess.

Taking adequate precautions can reduce the risk of ear infections. Wash hands frequently to prevent cold and other infections that may lead to otitis media. Breastfeeding reduces the risk of ear infections. Make sure to vaccinate the child according to the instructions of the doctor. This may protect the child from various infections. Reduce exposure to secondhand smoke.