- Unlike other life-threatening conditions, the people they affect are completely healthy unless they are exposed to the allergen. They and their families live a life of unremitting worry, with the constant mental refrain that any mistake can be a fatal mistake. And there are always mistakes
Is it really so mysterious? This line of thinking, called the "hygiene hypothesis," holds that when exposure to parasites, bacteria, and viruses is limited early in life, children face a greater chance of having allergies, asthma, and other autoimmune diseases during adulthood. In fact, kids with older siblings, who grew upon a farm, or who attended day care early in life seem to show lower rates of allergies.Currently, about 8 percent of children in the United States and about 2 percent of adults have diagnosed food allergies. It’s a mysterious epidemic.
A mounting body of research suggests that exposing infants to germs may offer them greater protection from illnesses such as allergies and asthma later on in life.
I have a cousin that is allergic to peanuts. Kid could easily die if he ate one. It's not because his mom didn't let him play in the dirt. Perhaps some seasonal allergies may be a result of this, but I think that those with life threatening allergic reactions do have a more "mysterious" debilitation.
I'm not trying to suggest that every case of food allergy is caused by lack of exposure to germs in early life, or that every case could have been prevented by exposure to germs, but this "hygiene hypothesis" makes quite a bit of sense to me. This page seems to confirm my suspicion that the HH is currently the most likely culprit, although research is stil ongoing.