Hygiene Hypothesis

The Hygiene Hypothesis was back in the news recently, following a story in The Wall Street Journal, 'Can Dirt Do a Little Good?'

As many parents know, the Hygiene Hypothesis attempts to explain the increased incidence of asthma, allergies, and other allergic type disorders in developed countries on the fact that we live in an environment that is almost too clean. Without exposure to the many bacteria, viruses and parasitic worms that children in poorer, developing countries are exposed to, a child's immune system can overreact and event turn on itself, leading to the development of allergies, asthma, and type I diabetes.

Avoiding allergies, asthma, and diabetes is not as simple as not washing your hands or living in a dirty home though or getting a lot of bacterial or viral infections. If that were the case, children in daycare, who get frequent infections, would have the lowest rates of allergies and asthma. Instead, it is important to keep in mind that this is a complicated and often controversial idea that is still being researched.

Experts studying the Hygiene Hypothesis have found a protective effect against allergic type diseases for children in large families with older siblings, children who lived on farms, and adults who had antibodies against the hepatitis A virus, Toxoplasma gondii, and herpes simplex virus 1 (which are usually childhood infections). Researchers are also studying if the rise in allergies and asthma could be from an increased use of antibiotics, alterations in normal intestinal bacteria, a decrease in the incidence of vaccine preventable infections,  or decreased levels of vitamin D. They are also studying whether there could be an association between the Hygiene Hypothesis and all kinds of conditions, from autism to obesity, or if it could be related to the parasitic worms in the soil that kids in developed countries aren't exposed to as often anymore.

If true, one thing that is certain about the Hygiene Hypothesis is that advances in hygiene and sanitation has greatly decreased the deaths and complications from many of the things in developing countries that may protect them from allergies and asthma. Hopefully we can find a way to stay clean and still avoid these allergic type conditions.

What would you do to keep your kids from getting allergies or asthma? Would you expose them to pinworms if experts found that to be protective? Or give them a drink supplemented with microscopic pig whipworm eggs?

Related:
Vaccine Preventable Illnesses
Allergies
Hard-to-Control Asthma