Most kids will get at least one ear infection by age 3. In recent years, rates of ear infections have been steadily declining, but about 5 million new cases are still diagnosed in the U.S. each year, resulting in 30 million physician visits and 10 million antibiotic prescriptions, according to the American Academy of Pediatrics.

This month, Dr. Lewis First, head of pediatrics at the University of Vermont Children's Hospital, explains why many of those antibiotic prescriptions are unnecessary — and can even do more harm than good — and offers an alternative treatment. Lend him your ears?

KIDS VT: First, why are children more inclined than adults to get ear infections?

LEWIS FIRST: There's a small tube inside your head that runs from your middle ear to your nose, called the eustachian tube. Because these tubes are narrower, shorter and more flexible in kids, they're more prone to blockages should fluid get in them, which can occur with a cold and runny nose. Additionally, kids' glands at the back of their throat, called adenoids, can get inflamed due to infections, which can also block the exit point of that tube so fluid in the tube cannot drain out. When fluid gets trapped, it becomes a stagnant pool of sorts that is great for growing bacteria and viruses. Eventually the pressure of the fluid and germs building up pushes against the eardrum, causing the ear pain characteristic of an ear infection.

KVT: What causes childhood ear infections, and why are they becoming less common?

LF: Ear infections are caused either by viruses or bacteria. We now know that, in Vermont, about 75 to 80 percent of the germs that cause children's ear infections are viruses, which antibiotics do not kill. In a fairly well-immunized community, you're going to see fewer ear infections nowadays because the common bacterial organisms that often cause them are covered by the pneumococcus vaccine and the H-flu vaccine. Most children with viral ear infections get better without doing anything other than treating the earache pain. Lower rates of parental smoking and higher rates of breastfeeding have also lowered the incidence of ear infections.

KVT: Why does breastfeeding reduce the incidence of ear infections?

LF: There are substances in breast milk that may protect your child from some respiratory germs that can cause ear infections. We now know that babies who are breastfed for at least six months are less likely to develop bacterial or viral infections of the respiratory system. Also, a breastfed baby is constantly swallowing, which opens and closes the eustachian tubes. Because you breastfeed more often than you bottle-feed, it may be that you're keeping those tubes open more often and not allowing fluid to build up.

KVT: Why don't we want to use antibiotics too often?

LF: We want to save them for when we really need them. The more we use them, the more we breed antibiotic-resistant germs. We don't want a child to get an illness in the future that we don't have medications to treat because they received too many unnecessary antibiotics to treat viral infections. Plus, antibiotics can come with side effects, such as nausea, stomach pain, diarrhea and disruption of the microbiome, or "good germs," that reside in our bodies.

KVT: Any exceptions to that rule?

LF: Babies under 6 months old are more at risk for bacterial infections, because their immune systems are not yet mature. If an infant under 6 months has an ear infection that goes untreated, it can put the child at risk for complications that can include meningitis, mastoiditis and even hearing problems. Also, if a child has an anatomic complication, such as cleft palate, an immune disorder or Down syndrome (which may mean a child has shorter eustachian tubes than normal, predisposing them to infections), then we're more apt to use an antibiotic. If an ear infection is deemed severe — meaning both ears are infected, the child is miserable and the eardrums are bulging — and the child is 6 months to 2 years old, we'll also use antibiotics. If the child is over 2 years old, we strongly recommend against using antibiotics for the first 48 to 72 hours, which should be all the time it takes for a virus to be killed by a child's immune system such that the ear pain improves. During this time, a child should be kept well hydrated, and the inflammation should be treated with acetaminophen or ibuprofen.

KVT: If a doctor prescribes an antibiotic for an ear infection in an older child, should parents question that decision?

LF: We always want parents to be educated and ask why an antibiotic is being used. As health care providers, we're more apt to be asked by parents why an antibiotic is not being prescribed. When one is prescribed, the provider should explain why the benefits of avoiding a bacterial infection outweigh the risks.

KVT: How do you know if an earache is caused by water remaining in the ear after swimming?

LF: If gently tugging on your child's ear causes them to say, "Stop it!" that pain is probably not a middle-ear infection. If your child develops swimmer's ear, which is an infection of the outer ear canal due to moisture getting stuck inside the entrance of the ear, a good home remedy is a mixture of vinegar and rubbing alcohol, in equal parts. Put a few drops in both ears two or three times a day. That will dry out the ear and reduce the inflammation. Children should also stay out of the pool or lake for a week or so.

KVT: What else can cause ear pain?

LF: Ear infections are often accompanied by cold symptoms and a fever. If you have just irritability and no fever with a baby, the child could be cutting a tooth. If it's a toddler, some amazing foreign objects can end up in the ear. Or it could be bad earwax. Your health care professional may want to see your child to see if there's something else going on other than just an ear infection, but if it is, again, don't expect them to automatically give antibiotics, especially if your child is over 2 years of age.