Incidence

Ear infections are the most common diagnosis and reason for physician office visits in the pediatric population. Otitis media (OM) is an infection of the middle ear and is the reason for the majority of antibiotic prescriptions for children. Almost all children will have at least one ear infection within the first few years of life. Many will have several episodes. By the age of six, ear infections in children generally become less frequent. The lack of development of the eustachian tubes, the tubes that drain the middle ear fluid into the back of the mouth/throat, in the first few years of life is responsible for many ear infections. Ineffective draining of this fluid causes a fluid build-up behind the eardrum that predisposes young children to ear infections.

Definitions

Acute otitis media is a middle-ear infection that has a rapid onset with sudden development of signs and symptoms. Otitis media can be associated with a fluid collection (effusion) within the middle ear and can be caused by bacteria, viruses, or a combination of the two.

Who is affected?

Certain environmental factors influence OM. Breast-fed infants tend to get fewer ear infections earlier in life than do formula-fed babies. Children who attend large daycare centers have greater risk than those who do not. Thirdly, children exposed to cigarette smoke on a regular basis may develop more infections. Ear infections are more common in fall, winter, and early spring, when upper respiratory infections are more common than in other seasons.

Approximately one third of children in the United States are especially prone to developing ear infections, with these children having at least three infections each by the time they are three years of age. Male children, Native Americans, and some other ethnic and geographical groups have a higher risk of ear infections than do other children. Children who develop their first infections within the first few months of life or have a sibling with recurrent OM are also at higher risk of being "otitis prone". Additionally, children who were not breast-fed as infants are at a greater risk.

Symptoms

The findings and symptoms associated with OM are often vague, especially in infants and young children. OM can occur alone or can be part of an upper respiratory tract infection that may include cough, runny nose, and fever. Pain usually occurs with OM, but may manifest only as ear pulling or general irritability in infants and young children. Fever is not typically present with OM, but may occur, especially when OM is associated with a systemic (generalized) illness with other symptoms.

Diagnosis

The diagnosis of OM is generally made on clinical grounds: by observing the appearance of the tympanic membrane (eardrum) for redness, buldging, and lack of movement when an air jet is directed at the eardrum. The most precise way to diagnose an ear infection is to take a sample of fluid from the inner ear by sticking a needle through the tympanic membrane. This exposes children to unnecessary risk, however, and is done only in extreme circumstances or resistant infections.

Treatment

Otitis media is treated with antibiotics. In general, amoxicillin and ampicillin are the most common antibiotics in children who are not allergic to penicillin. Patients allergic to penicillin are generally treated with erythromycin, although many alternatives are available and acceptable. Bacteria that are resistant to these antibiotics are still relatively uncommon in the U.S.

The need for antibiotics is still debated, as many cases of OM caused by bacteria will resolve without antibiotics. In addition, approximately one-third of OM cases are caused by viruses, which do not require antibiotic treatment. Therefore, approximately 60% of ear infections will get better without any treatment. OM can cause complications including hearing impairment, infection of the bones of the inner ear and mastoid (a skull bone), and even learning disabilities if ear infections cause sustained hearing impairment. Because of these potential complications, OM is routinely treated in the U.S.

Tympanostomy tubes (tubes that go through the eardrum and drain the middle ear fluid into the ear canal) are sometimes placed in children in which one or more of the following occurs: OM does not resolve with antibiotics, the infection recurs frequently (at least three episodes in six months), or OM is associated with hearing loss or an infection of bone. In some children with recurrent ear infections, antibiotics are given continuously to attempt to prevent infection, which is sometimes done before tubes are placed.