By Mark A. Kelley, MD |1/30/18
Founder, HealthWeb Navigator
Chances are you or someone you know has experienced an allergic reaction at some point. The statistics are eye-opening:
Allergies affect as many as 30% of American adults and 40% of children in the U.S. An estimated 20% of Americans have hay fever; about 4% of children and adults have a food allergy; and 10-20% of children and 3% of adults have significant skin allergies. Also common are allergies to dogs and cats.
Thankfully medical science can prevent and even eliminate some of these conditions. But how?
Our immune system is finely tuned to recognize and repel invaders, especially bacteria and viruses. An allergy develops when the body’s immune system detects a foreign protein and reacts to its presence.
Take the example of pollen. Most people have no problems with pollen. However, anyone with seasonal rhinitis (like me) suffers through the pollen season with a runny nose and cough.
Peanuts are the source of another common allergy. Most people have no problem with peanut products, but for others, peanut consumption can be dangerous. When exposed to a peanut product, these patients can develop serious breathing problems within minutes. Without treatment, this reaction can lead to life-threatening shock.
Of course, the best defense against an allergy is to avoid exposure to the agents that trigger it. Never eat peanuts if you are allergic; stay away from grass and flowers in pollen season; and give away your pet if you are allergic to it.
But sometimes these steps are impractical. For the peanut allergy, any food can be risky because peanut products are common in many foods. In pollen season, staying inside may be impossible if you work outside. As for a cat or dog allergy, patients are very reluctant to part with their pets.
Another way to fight an allergy is to “teach” the body to be more tolerant to allergens. The key is to introduce the offending proteins to the immune system in very small doses. This therapy of “allergy shots” has been around for decades. Small injections of the offending allergy protein (like ragweed) tone down the immune system so that any future reaction produces minimal symptoms. This approach is called “immunotherapy.”
For decades, this tolerance-building approach has been widely used for common allergies such as pollen and animal dander. With new technology, the allergens can now be delivered more easily, either under the tongue or orally, instead of by injection.
New evidence suggests that tolerance develops naturally in early childhood. From birth to about 4 years of age, the immune system seems to have a learning curve about how and when to react to allergens like animal dander and peanuts.
It was once thought that if children had less exposure to allergens, they wouldn’t be as likely to develop an allergy. For years, parents were advised to keep peanuts and other complex food away from children until the age of four. Similar advice pertained to exposure to pets.
Recent research has changed this thinking. New studies have shown that infants introduced to oral peanut extract before the age of one have much lower rates of peanut allergy. In other studies, children who grow up around domestic animals and pets have much lower rates of animal allergies and hay fever. This research suggests that childhood exposure to some allergens teaches the immune system tolerance and reduces the likelihood of developing some allergies.
Most mild allergies are easily treated and prevented. However, others are more serious, their therapies more complex. It is wise to discuss any allergies with your doctor and, if necessary, consult an allergy specialist.