Trusted Advice for All Kinds of Allergy Questions
Irina Dawson, MD, joined the team at Allergy Partners of Fredericksburg in October 2020, after completing her fellowship in adult and pediatric allergy and immunology at the University of South Florida-Johns Hopkins All Children’s Hospital in St. Petersburg, FL. Dr. Dawson was drawn to Fredericksburg when her husband, a Marine judge advocate, was stationed at Marine Corps Base Quantico. She was drawn to the field of allergy medicine because of her fascination with the immense complexity of the body’s immune system. As our March Expert, Dr. Dawson offers her knowledge on food allergies and other related issues parents may be wondering about.
What is exciting to you about the field of allergy medicine?
I did my pediatric residency at the University at Buffalo, N.Y., which was the first exposure I had to allergy and immunology. Having rotated with several immunologists and allergists, it really opened my eyes to the field and I instantly fell in love with it. The immune system is highly complex and requires a multitude of checks and balances. When the fine balance is lost disease can develop. Such as the chase with an underactive or poorly functioning immune system will often lead to recurrent infections and immunodeficiency. On the other hand, an overactive immune system can lead to allergies and autoimmune disease. Over the past few decades, we have seen so much advanced research in these fields. We are identifying new ways to treat diseases that are tied to problems with the immune system with modalities such as gene therapy and bone marrow transplant. Our understanding of the mechanisms behind these conditions has grown, and it is helping us to target food allergy and other conditions in a lot of different ways.
What is new in our understanding of how food allergy works, especially in children?
In the early ‘90s and 2000s, the recommendation was to hold off on introducing potentially allergic foods until children were much older. During that time, we saw a significant increase in the number of food allergies, particularly peanut allergies. From 2005 to 2015, the prevalence of peanut allergy among children in Western countries actually doubled, according to a pivotal study known as the Learning Early About Peanuts—or LEAP—Trial. The LEAP Trial showed us that children who were introduced to peanuts earlier in life were becoming less allergic to these foods. Now the pendulum has swung in the other direction and we are urging early introduction—between 4 to 6 months of age—with age-appropriate foods to limit the development of food allergy.
Many parents avoid peanut butter with their infants not only because of previous advice about allergies, but also because peanut butter can be a choking hazard. Are there safer ways to introduce it?
There is a snack called Bamba puffs that almost look like cheese puffs, but have peanut in them. These puffs were popular among children in Israel when the LEAP study was conducted. Researchers found that Israeli children who had been consuming Bamba puffs had a much lower prevalence of peanut allergy than children in the U.K., who had avoided peanuts as infants. You can also add a very small amount of peanut butter to formula or breast milk to safely introduce it at this age.
What else do we know about the prevalence of food allergies and what might cause it?
The emergence of food allergies in the last two decades has a lot to do with the immune system not being active enough. There is something called the “hygiene hypothesis,” which stipulates that extremely clean environments in the post-natal period fail to provide necessary exposure to germs required to educate the immune system. Decreasing incidence of infections has led to increase in allergic diseases and autoimmunity. In fact, developed countries with low rates of parasitic infections have much higher rates of food allergies and autoimmune diseases when compared to developing countries. Having a child exposed to his or her environment in safe ways, and not always being in a completely germ-free environment, provides important opportunities for the immune system to act and develop appropriately. In other words— playing in the dirt isn’t always a bad thing.
How do you work with families to help them figure out what is causing what may look like an allergic reaction in their child?
My approach starts with a thorough history. Sometimes what a parent might think is a food allergy can be something entirely different. There are a lot of adverse food reactions which can mimic food allergy. I often see children undergoing extensive food allergy testing with lots of positive results to various foods. They are told to avoid these foods even though they were previously eating them with any issues. This can lead to nutritional deficiencies and unnecessary anxiety around eating, so we really want to narrow it down to the specific foods that are causing a reaction. The important thing to know about food allergy is that it is consistent and reproducible—every time you eat that food, you are going to see a reaction. Food allergy testing, whether it is bloodwork or skin testing, can lead to false positive results. That’s why it’s so important to do a thorough history and talk about each reaction including timing, symptoms, and the foods involved. A complete history combined with food allergy testing are needed for a precise diagnosis.
For allergies in general—whether they be food or seasonal allergies—are they consistent over a person’s lifetime, or can they develop later in childhood, or even adulthood?
Food allergies are more common in children. Milk, egg, and wheat allergy tend to develop early in life with majority outgrowing these allergies by school age or teenage years. Allergies to peanuts, tree-nuts, and shellfish tend to be more lifelong. Shellfish is an allergen that tends to develop later in life, even in adulthood. It’s definitely not as common to develop food allergies at an older age, but shellfish is the exception.
For seasonal allergies and allergies to things like pet dander, these are a product of a person’s environment, and often we see can see new allergies develop with different environmental exposure. The classic example is a college student who goes away to college, comes back for winter break and all of a sudden cannot be around the family cat or dog, even though it was never a problem before. Often it happens when you have a change in your environment that the allergies become more pronounced. When we stay in the same environment, we become desensitized to it. Upon re-exposure allergy symptoms can suddenly develop.
What is exciting to you about working in the Allergy Partners practice?
For many years, the treatment for food allergy was considered avoidance. Once you were labelled allergic, you just avoided the food. Now, we are seeing oral immunotherapy becoming a tool that we can use to try to alter the immune response. It’s similar to allergy shots. We take the allergic food and start giving it to the child in tiny doses, hoping they can build up their tolerance to that food. This is a fairly new treatment. At Allergy Partners of Fredericksburg, Dr. Nicholas Klaiber is currently conducting oral immunotherapy, and I hope to begin doing it as well. It is definitely the future. If we start this process early enough, we can even change the outcome of the food allergy, to where the child can even outgrow it.
To learn more about Allergy Partners of Fredericksburg or to schedule a consultation, visit allergypartners.com/Fredericksburg, or call 540-371-5660.