Of all infections seen in childhood, ear infections stand out as very common and quite distinctive.
Children vary in the number they experience. Some parents wonder what all the fuss is about, their children never experience one.
Others suffer watching their child cry in pain every other week.
Not long ago, the main germs that caused ear infections were free to infect without any hindrance. Now we use several immunizations that, we hope, would have a big impact, reducing the number of children who suffer this painful infection.
The month’s journal Pediatrics delivers an important new look at where ear infections stand in the United States in 2017.
What is an Ear Infection?
For the purposes of this post, an ear infection will refer to a very specific infection, namely, acute otitis media.
To understand what either phrase, ear infection or acute otitis media means, let’s take a look at the structures of the ear:
Notice in this drawing, the ear has three regions: outer, middle, and inner.
The outer ear is anything from the eardrum to the air around the head. It includes all the ear that most of us can see, including the ear lobe, the ear itself, and a small hole that leads to a canal to the eardrum. It is the canal, the little hollow tube that connects the outer visible ear to the eardrum where swimmer’s ear occurs. That is not what we mean here in this post by ear infection.
The inner ear is the part of the ear that is inside the skull, it’s not really part of the ear as we think about it. It is the ear in the sense that this is where vibrations of sound turn into nerve signals, the first step towards creation of hearing. It is also where shifts in motion of the body are turned into nerve signals, the first step towards the creation of balance.
Ear infections are all about the middle ear. It is a space that is defined by being between the outer ear and the inner ear. Technically, it has much more to do with the nose than the ear. It is a pocket off the nose, lined by the same sort of tissue as the nose. So when the nose makes mucus, so does the middle ear. The only items in the middle ear are the 3 tiny bones of hearing, the hammer, anvil, and stirrups, these tiny bones and their joints transmit the vibrations of the vibrating ear drum to the fluid inside the cochlea- the organ of hearing in the inner ear.
Since the middle ear is really a pocket of the nose, if the nose makes mucus, and the middle ear makes mucus, then that mucus in the middle ear must drain, get absorbed, or it festers.
An ear infection is when mucus in the middle ear does not drain or clear, but festers, turning into an enlarging ball of pus.
When that mucus gets infected the bacteria multiply and our white cells pile on, making a ball that expands. It can’t push at all against the bone that is the boundary of the inner ear, so it stretches towards the outer ear by stretching the eardrum.
It is that stretching of the eardrum that causes all the pain of the ear infection.
Why worry about ear infections?
There are really two major reasons we pay any attention to ear infections:
- They hurt. They really hurt, and it’s the pain that lets us know one is present, and the pain that drives nearly all treatment of them.As we saw above, if the pus ball that is the ear infection grows, it stretches the ear drum, and that’s what hurts. So if you take an antibiotic that shrinks the pus ball, even a tiny bit, the pressure on the ear drum drops dramatically. Voila! Pain eases and goes away.
- The bacterial infection in the middle ear can spread. This turns out to be a fairly rare event. We have only seen it happen once or twice over a 30 year period. But when it happens, it usually spreads to the bones surrounding the inner ear. Ear infections almost never enter the body or go anywhere else.
Why do some kids get a lot and others get no ear infections?
This has everything to do with drainage. Remember an ear infection is a ball of pus behind the ear drum, in the space we call the middle ear space. And, the start of every ear infection is at least a drop of extra mucus in that space that fails to drain.
How does a drop of mucus in the middle ear space drain? Into a tube called the Eustachian tube that connects the middle ear space to the nose. This is a tiny tube, and only works if the tube pulses waves that milk stuff in the middle ear space down to the nose.
If that tube stops pulsing waves or gets blocked, nothing drains from the middle ear space, and whamo, the next drop of mucus can fester into a ball of pus.
By the way, if that tube gets blocked, air can’t flow through it either and you get that sense of ears “being clogged” when going up and down in altitude (down a steep road, landing in an airplane).
So, some kids have very open and active Eustachian tubes, they will get few if any ear infections. Others have tubes that are small, or very horizontal, or block easily, they could get an ear infection with any collection of nasal mucus- with colds, allergies.
So, what’s new in the world of ear infections?
Let’s start with how they were when you were kids- say in the 1980’s.
Back then about 3/4 of ear infections had a bacteria as the causative germ, about 1/4 were caused by viruses.
Amoxicillin cured about 80% of the bacterial cases.
No vaccines were available to prevent ear infections from any germ.
That was then, now here is now:
- Every year in the United States about 5 million cases of ear infection occur in children.
- 10 million prescriptions for antibiotics
- 30 million doctor’s visits.
Let me just say here that it makes little sense to me that there should be twice as many Rx’s for ear infections, and 3 times as many doctors visits for ear infections, as there are ear infections. More on that later.
Some brand new insights from current data
#1- A 5 day course is now shown to be as good as a 10 day course.
#2- As you get older, you are less likely to get an ear infection. One year olds had a 23% chance of having one, 3 year olds, a much smaller chance. The peak age was one year old. In 2016 about 60% of kids had an ear infection by age 3, and 24% 3 or more. That is much less than in 1989 when over 80% of kids had an ear infection by age 3 and over 40% had 3 or more episodes.
#3- 95% of children treated for an ear infection were cured, that is no ear infection for at least 2 weeks after treatment ended.
#4- Breastfeeding has little protective impact. Curiously, there was no difference in the chance of getting an ear infection between those babies never breastfed versus those exclusively breast fed in the first 6 months of life, at ages 0-3 years old.
#5- Having allergies has little impact in causing ear infections to happen.
#6- Having lots of colds clearly increases the chance of getting an ear infection, and that is seen in day care.
#7- When the nation started immunizing against the bacteria called the pneumococcus, with the vaccine called either PCV or prevnar, the chance of that bacteria causing otitis media dropped, but other bacteria took its place, so the overall chance of getting a bacterial cause for your ear infection remains about 75%.
#8- The children with ear infections all did pretty well, no serious complications were reported.
- Ear infections. By far one the most common illnesses kids experience. Only colds and stomach flus are more common.
- The use of the pneumococcal vaccine, AKA Prevnar or PCV, has led to a dip in the number of kids with ear infections, and the number who have 3 or more by age 3.
- Allergies, and breast feeding, had little impact on the chance of getting an ear infection.
- The #1 item that led to having more ear infections was getting a cold. Makes sense, if mucus in the middle ear causes ear infections, then causes of tons of mucus should be related, and nothing makes mucus like a cold.
- THIS IS A BIG FINDING- a short 5 day course of antibiotic works as well as 10 days, still delivers a 95% cure rate.
Putting it all together, ear infections come and go, they cause little harm, beside the pain. They are less common now than 30 years ago, but still around.
Antibiotics cure the pain 95% of the time, but it is also the case that many cases never get diagnosed and clear on their own.
So, ear infections can be painful, but are only very rarely harmful. A 5 day course of oral antibiotic makes sense if pain is significant.
Given that they are generally so harmless, and that a 5 day course of antibiotic has a 95% chance of cure, it makes little sense to place ear tubes to prevent them, unless the pain they create is so frequent that treatment with antibiotic when pain occurs is not adequate to sustaining comfort.
And, stay tuned, Advanced Pediatrics continues to explore approaches to make the diagnosis even easier for families.
To your health,
Dr. Arthur Lavin