Ear infections are common in children, especially during the toddler years through age 3, according to the Mayo Clinic. An occasional ear infection isn't anything to worry about, but recurring or persistent infections need medical treatment. Symptoms of a toddler ear infection include pain, diminished hearing, trouble sleeping, irritability and sometimes a low fever. An ear infection is generally the result of fluid being trapped in the ear, but there are several reasons for the fluid to build up.
Infection
An ear infection is often caused by infections like a cold or sinusitis. The Mayo Clinic explains that the middle ear lining becomes swollen from the viral or bacterial infection, allowing fluids to build up behind the ear drum and block the eustachian tube. The eustachian tube is responsible for keeping pressure from building up by letting air move in and out of the middle ear, according to the Kids Health website. It is also responsible for transporting mucus from the middle ear into the throat. The virus or bacteria that caused the child's illness can travel up the eustachian tube from the nasal passages or the mouth and infect the inner ear when it gets trapped by the swollen eustachian tube.
Eustachian Tube Size
Toddlers often have a shorter, narrower eustachian tube that will grow with age. A short and narrow tube can increase the risk ear infection by doing a poor job of keeping germs out and allowing fluids that have been swallowed to make their way up to the inner ear, according to the Kids Health website. Germs normally travel in and out of the inner ear area by way of the eustachian tube, but when they can't escape due to the tube size, the result is a buildup of infectious agents. Shortly after birth, an infant's eustachian tube is tilted in a way that allows fluids that are swallowed to easily go up toward the ear. Toddlers who drink from a bottle, especially while lying down, are at risk of having the swallowed fluids make their way up the eustachian tube, too. As the child ages, the tube becomes straight.
Swollen Adenoids
The adenoids are in the upper throat near the eustachian tubes. The Mayo Clinic points out that normally the adenoid cells fight infection but they can get infected themselves. When the adenoid is infected, it can become swollen or enlarged, blocking the eustachian tube. The same infection that affects the adenoids can travel up the eustachian tubes as well. When the tubes can't function appropriately, fluids pool behind the eardrum and cause an ear infection.
