Messes come naturally to most kids – from using their food to decorate their faces and high chairs to spilling out pretzels in the backyard before eating each one.
But before you reach for the hand sanitizer, dirt and messes may serve a purpose. At least that’s what some allergy and asthma experts are researching as part of an intriguing theory called the hygiene hypothesis.
Understanding the hygiene hypothesis
“The hypothesis has been developed over a number of years to explain a surprising observation that researchers are still trying to fully understand,” said Dr. Rajeev Kishore, director of the allergy/immunology division at Akron Children’s Hospital.
That observation? “Children in areas that seem less hygienic, like farms where there’s constant exposure to bugs, have a lower incidence of allergies and asthma than those in areas you’d expect to be more ‘clean,’ like suburban areas and cities.”
The working theory is that kids’ immune systems are hardwired, courtesy of evolution, to ward off germs as they encounter them.
And when the immune system doesn’t have as many germs or bacteria to combat, it may react instead to things that wouldn’t normally be deemed harmful to the body, like pet dander, dust mites, and even peanuts and tree nuts.
Rising asthma and allergy rates
Asthma rates have been on a constant rise, according to the U.S. Centers for Disease Control and Prevention. In 2009, 1 in 12 people had asthma, compared with 1 in 14 in 2001. In children, the rate is 1 in 10.
Allergic conditions have equally troubling statistics. Currently, they’re the most common medical condition among children – while respiratory allergies seem to have leveled off over the last few years, skin and food allergies are still increasing.
While genetics can certainly play a role, said Dr. Kishore, it isn’t the only factor, which is why researchers are so focused on better understanding how, when and why kids develop asthma and allergies – along with ways to prevent it.
So can early exposure to dirt – or more specifically the germs and bacteria that comes with it – help safeguard kids against allergies and asthma?
“We’re not at the point with the research to say that definitively,” said Dr. Kishore. “But I do think part of the message is that parents don’t necessarily need to go overboard with constantly putting hand sanitizer on kids or keeping their environment spotless. Does that mean we should eat dirt – or have our kids eat dirt? I don’t think so. But what it does mean is that we don’t have to go overboard about hygiene.”
That said, Dr. Kishore recommends parents who have concerns about children’s allergies or asthma consult their pediatrician.
“There’s a perception, especially with asthma, that the child will outgrow it, but that’s simply not the case,” he said. “As with many chronic conditions, early recognition is important since the earlier we start treatment the better the outcomes are going to be.”