Causes of Hearing Loss in Children

Otitis Media

What is otitis media?

Otitis media is an inflammation in the middle ear (the area behind the eardrum) that is usually associated with the buildup of fluid. The fluid may or may not be infected.

Symptoms, severity, frequency, and length of the condition vary. At one extreme is a single short period of thin, clear, noninfected fluid without any pain or fever but with a slight decrease in hearing ability. At the other extreme are repeated bouts with infection, thick "glue-like" fluid and possible complications such as permanent hearing loss.

Fluctuating conductive hearing loss nearly always occurs with all types of otitis media. In fact it is the most common cause of hearing loss in young children.

How common is otitis media?

Otitis media is the most frequently diagnosed disease in infants and young children (1). Seventy-five percent of children experience at least one episode of otitis media by their third birthday. Almost one-half of these children will have three or more ear infections during their first 3 years of life (2). Health costs for otitis media in the United States have been reported to be $3 billion to $5 billion per year (3).

Why is otitis media so common in children?

The eustachian tube, a passage between the middle ear and the back of the throat, is smaller and more nearly horizontal in children than in adults. Therefore, it can be more easily blocked by conditions such as large adenoids and infections. Until the eustachian tube changes in size and angle as the child grows, children are more susceptible to otitis media.

How can otitis media cause a hearing loss?

Three tiny bones in the middle ear carry sound vibrations from the eardrum to the inner ear. When fluid is present, the vibrations are not transmitted efficiently and sound energy is lost. The result may be mild or even moderate hearing loss. Therefore, speech sounds are muffled or inaudible.

Generally, this type of hearing loss is conductive and is temporary. However when otitis media occurs over and over again, damage to the eardrum, the bones of the ear, or even the hearing nerve can occur and cause a permanent, sensorineural hearing loss.

Can hearing loss due to otitis media cause speech and language problems?

Children learn speech and language from listening to other people talk. The first few years of life are especially critical for this development.

If a hearing loss exists, a child does not get the full benefit of language learning experiences.

Otitis media without infection presents a special problem because symptoms of pain and fever are usually not present. Therefore, weeks and even months can go by before parents suspect a problem. During this time, the child may miss out on some of the information that can influence speech and language development.

How can I tell if my child might have otitis media?

Even if there is no pain or fever, there are other signs you can look for that may indicate chronic or recurring fluid in the ear:

• Inattentiveness
• Wanting the television or radio louder than usual
• Misunderstanding directions
• Listlessness
• Unexplained irritability
• Pulling or scratching at the ears

What should I do if I think that otitis media is causing a hearing, speech, or language problem?

A physician should handle the medical treatment. Ear infections require immediate attention, most likely from a pediatrician or otolaryngologist (ear doctor). If your child has frequently recurring infections and/or chronic fluid in the middle ear, two additional specialists should be consulted: an audiologist and a speech-language pathologist.

An audiologist's evaluation will assess the severity of any hearing loss, even in a very young or uncooperative child, and will indicate if a middle ear disorder is present.

A speech-language pathologist measures your child's specific speech and language skills and can recommend and/or provide remedial programs when they are needed.

Will my physician refer my child for these special evaluations?

As a parent, you are the best person to look for signs that suggest poor hearing. The American Academy of Pediatrics recognizes this when it states, "Any child whose parent expresses concern about whether the child hears should be considered for referral for behavioral audiometry without delay".

Parents should not be afraid to let their instincts guide them in requesting or independently arranging for further evaluation whenever they are concerned about their children' s health or development.

Congenital Causes

The term congenital hearing loss implies that the hearing loss is present at birth. It can include hereditary hearing loss or hearing loss due to other factors present either in utero (prenatal) or at the time of birth.

Genetic factors are thought to cause more than 50% of all incidents of congenital hearing loss in children (4). Genetic hearing loss may be autosomal dominant, autosomal recessive, or X-linked (related to the sex chromosome).

In autosomal dominant hearing loss , one parent who carries the dominant gene for hearing loss and typically has a hearing loss passes it on to the child. In this case there is at least a 50% probability that the child will also have a hearing loss. The probability is higher if both parents have the dominant gene (and typically both have a hearing loss) or if both grandparents on one side of the family have hearing loss due to genetic causes. Because at least one parent usually has a hearing loss, there is prior expectation that the child may have a hearing loss.

In autosomal recessive hearing loss , both parents who typically have normal hearing, carry a recessive gene. In this case the probability of the child having a hearing loss is 25%. Because both parents usually have normal hearing, and because no other family members have hearing loss, there is no prior expectation that the child may have a hearing loss.

In X-linked hearing loss, the mother carries the recessive trait for hearing loss on the sex chromosome and passes it on to males, but not to females.

There are some genetic syndromes,in which, hearing loss is one of the known characteristics. Some examples are Down syndrome (abnormality on a gene), Usher syndrome (autosomal recessive), Treacher Collins syndrome (autosomal dominant), Crouzon syndrome (autosomal dominant), and Alport syndrome (X-linked).

Other causes of congenital hearing loss that are not hereditary in nature include prenatal infections, illnesses, toxins consumed by the mother during pregnancy or other conditions occurring at the time of birth or shortly thereafter. These conditions typically cause sensorineural hearing loss ranging from mild to profound in degree. Examples include:

• Intrauterine infections including rubella (German measles), cytomegalovirus, and herpes simplex virus
• Complications associated with the Rh factor in the blood
• Prematurity
• Maternal diabetes
• Toxemia during pregnancy
• Lack of oxygen (anoxia)

Acquired Causes

Acquired hearing loss is a hearing loss which appears after birth, at any time in one's life, perhaps as a result of a disease, a condition, or an injury. The following are examples of conditions that can cause acquired hearing loss in children are:

• Ear infections (otitis media) (link to specific section above)
• Ototoxic (damaging to the auditory system) drugs
• Meningitis
• Measles
• Encephalitis
• Chicken pox
• Influenza
• Mumps
• Head injury
• Noise exposure

Finding Help

How can I find an audiologist or speech-language pathologist?

Search ASHA ProFind or contact the American Speech-Language-Hearing Association's Action Center, 2200 Research Boulevard #425, Rockville, Maryland 20850. Phone: 800-638-8255 or 301-296-5700.

Where can I find a pediatric audiology facility?

Search EHDI-PALS, a website with a national pediatric audiology facilities directory and great educational resources for families.

References

1. Dhooge, I.J. (2003). Risk factors for the development of otitis media. Current Allergy and Asthma Reports, 3: 321–325.

2. National Institute on Deafness and Other Communication Disorders. (2002). Otitis media (ear infection) (NIH Publication No. 974216). Bethesda, MD: Author.

3. Alsarraf, R., Jung, C.J., Perkins, J., Crowley, C. & Gates, G.A. (1998). Otitis media health status evaluation: A pilot study for the investigation of cost-effective outcomes of recurrent acute otitis media treatment. Annals of Otology, Rhinology and Laryngology, 107: 120–128.

4. Canalis, R.F., & Lambert, P.R. (2000). The ear: Comprehensive otology. Philadelphia: Lippincott Williams & Wilkins.