Ear pain is one of the most common reasons that young children go to the doctor, and acute otitis media – which means “middle ear infection” – is the most frequent cause for the use of antibiotics in children under 5 years of age. Twenty-five percent of children will have an ear infection by their first birthday, and 60% by age 5.
As a pediatrician, I see children in my clinic daily for ear infections. Because these are associated with viral upper respiratory infections, we typically see most ear infections in the fall and winter, when influenza and cold viruses are prevalent. However, with near-universal mask-wearing due to COVID-19 last winter and many children out of school, the number of viral upper respiratory infections dropped drastically. As a result, we saw very few ear infections in our clinic.
This summer, with the lifting of COVID-19 restrictions, we saw a return of many respiratory viruses, and with them, middle ear infections.
How an Ear Gets Infected
The middle ear space, which is the space behind the ear drum, is connected to the back of the throat via the eustachian tube. When people, especially children, get congested, they tend to collect fluid in this space.
If a child has a cold and stays congested for awhile, that buildup of fluid can become infected, usually by bacteria that have migrated from the back of the nose or the throat. As children grow, their skull lengthens, and the eustachian tube can drain more easily because it begins to slant downward toward the back of the throat. Over time, children also build immunity to common cold viruses and get sick less often, so overall ear infections decrease with age.
The three most common bacteria that cause middle ear infections are Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis.
Interestingly, before we had pneumococcal vaccines against Streptococcus pneumoniae, these bacteria caused about 60% to 70% of all ear infections in children between 6 months and 5 years of age. But after these vaccines were added to the childhood immunization series in 2001, overall rates of ear infections dropped, and the proportion due to strep pneumo has gradually decreased to 15% to 25%. Haemophilus influenzae now causes the majority of ear infections.
Guidelines for Diagnosing and Treating
The American Academy of Pediatrics’ most recent guidelines for acute otitis media, which is diagnosed by physical exam, came out in 2013. A doctor will look in a child’s ears with an instrument called an otoscope to see if the ear drum is red or bulging or if it has fluid behind it. Sometimes the doctor will use a small puff of air in the ear to see if the ear drum moves well. If there is an infection behind the ear drum, it will not move with the air.