Food allergy, nasal allergy, and asthma have all been on the rise for the past several decades, and there doesn’t seem to be anything that we can do to slow down this trend…until now. A recent review article in the Journal of Allergy and Clinical Immunology has given us clues as to how these diseases start and how we can prevent them from starting in the first place.
So, how do allergies start in the first place? When the immune system is still developing in a very young child, it is still trying to figure out what types of defenses it should build in order to best protect the body from foreign invaders. Most people have a fairly good first-line defense against these foreigners already–the skin. When this wall of defense has cracks in it, the invaders (ie bacteria, allergens, etc) can more easily cross over and directly affect the young immune system’s decisions. If the right combination of genetics and exposure exists, then the immune system decides to make antibodies to those allergens–not just any antibody but IgE antibodies–and that is where all of the trouble begins.
Once your immune system has made these special “allergic antibodies” (i.e. IgE antibodies), the next time it encounters that allergen again it may get the system all fired-up and decide to freak out and cause an allergic reaction. People that don’t have these antibodies can just eat whatever they want without worrying about an allergic reaction. It’s easy enough to test for these IgE antibodies, but is there a way to prevent the immune system from making those bad decisions in the first place?
The answer to allergy prevention may be as simple as avoiding the things that could get your immune system in trouble in the first place. Don’t want your kids to have hood rat friends? Maybe don’t expose them to hood rats all the time. You don’t want to get fat? Maybe don’t have so many Oreos and cheese puffs scattered around the house. The same idea could be applied to allergy and an all too impressionable developing immune system. The new thinking is that perhaps if we beef-up the skin barrier and fix all of those tiny cracks in it, then the immune system will be less likely to make the wrong types of antibodies to things it really shouldn’t. By regularly applying a variety of moisturizing creams or skin barriers to infants, it appears that the chances of developing food allergy, asthma, etc goes down.
There is still a lot we don’t really know about who will get allergies and who won’t, but at least we are starting to better understand the basics. In the past, new parents who have a history of allergies have been content to accept their fate that the odds of their children having some type of allergic disorder is overwhelmingly against them. With these new insights, perhaps they will finally be able to tip the odds in their favor.
J Allergy Clin Immunol 2017;139:1723-34.