Definition of Infection, middle ear

Infection, middle ear: Acute middle ear infection, medically called acute otitis media is inflammation of the middle ear. Acute otitis media typically causes fluid in the middle ear accompanied by signs or symptoms of ear infection: a bulging eardrum usually accompanied by pain; or a perforated eardrum, often with drainage of purulent material (pus).

Otitis media is the most frequent diagnosis in sick children in the U.S., especially affecting infants and preschoolers. Almost all children have one or more bouts of otitis media before age 6.

The Eustachian tube is shorter in children than adults which allows easy entry of bacteria and viruses into the middle ear, resulting in acute otitis media. Bacteria such as Streptococcus pneumoniae (strep) and Hemophilus influenzae (H. flu) account for about 85% of cases of acute otitis media and viruses the remaining 15%. Babies under 6 weeks of age tend to have infections from different bacteria in the middle ear.

Bottlefeeding is a risk factor for otitis media. Breastfeeding passes immunity to the baby that helps prevent acute otitis media. The position of the breastfeeding child is better than the bottle-feeding position for Eustachian tube function. If a child needs to be bottle-fed, holding the infant rather than allowing the child to lie down with the bottle is best. A child should not take the bottle to bed. (Falling asleep with milk in the mouth increases the incidence of tooth decay).

Upper respiratory infections are a prominent risk factor for acute otitis media so exposure to groups of children as in child-care centers results in more frequent colds and therefore more earaches. Irritants such as tobacco smoke in the air also increase the chance of otitis media. Children with cleft palate or Down syndrome are predisposed to ear infections. Children who have acute otitis media before 6 months of age have more frequent later ear infections.

Young children with otitis media may be irritable, fussy, or have problems feeding or sleeping. Older children may complain about pain and fullness in the ear. Fever may be present in a child of any age. These symptoms are often associated with signs of upper respiratory infection such as a runny or stuffy nose or a cough.

The buildup of pus within the middle ear causes pain and dampens the vibrations of the eardrum (so there is usually transient hearing loss during the infection). Severe ear infections may cause the eardrum to rupture. The pus then drains from the middle ear into the ear canal. The hole in the eardrum from the rupture usually heals with medical treatment.