Causes of Otitis Media
The most common ear infection (otitis media) causes are bacteria and viruses that get inside the ear. People who are at risk for otitis media include children who are cared for in group settings, children who live with adults who smoke cigarettes, and infants who nurse from a bottle while lying down.
Bacteria or viruses that get inside the ear are the most common causes of otitis media. These bacteria or viruses can initially cause sore throats, colds, or other respiratory or breathing problems and then spread to the middle ear.
Bacteria or Viruses Within the EarBacteria or viruses reach the middle ear through the lining or the passageway of the Eustachian tube; they can then produce infection. Infection causes swelling of the lining of the middle ear, blocking of the Eustachian tube, and migration of white cells from the bloodstream to help fight the infection. In this process, the white cells accumulate, often killing bacteria and dying themselves, leading to the formation of pus (a thick yellowish-white fluid) in the middle ear.
As the fluid increases, the child may have trouble hearing because the eardrum and middle ear bones are unable to move as freely as they should. As the infection worsens, many children also experience severe ear pain. Too much fluid in the ear can put pressure on the eardrum and eventually tear it.
While not direct otitis media causes, there are some things that can increase a person's chance of developing an ear infection. People who are at risk for otitis media include:
- Children who are cared for in group settings
- Children who live with adults who smoke cigarettes
- Infants who nurse from a bottle while lying down
- People with allergies
- People with certain birth defects such as cleft palate, Down syndrome, and nervous system abnormalities.
Although certain risk factors can be avoided, it is important to keep in mind that avoiding risk factors does not guarantee that your child will not get otitis media. Some people are more sensitive than others to factors that can cause ear infections. Talk to your doctor about methods of ear infection prevention that might be effective for you or your child.