Hugh Sampson, M.D.
Director, Jaffe Food Allergy Institute
Icahn School of Medicine at Mount Sinai
Your child, who is allergic to peanuts and tree nuts, just received a coveted invitation to a big birthday bash. She is excited... but you're terrified. What foods will they serve at the party? Will they use the same ice cream scoop for the butter pecan as the vanilla? Will they offer candy containing a trace amount of peanuts?
More and more American parents today are living with the fear that their food-allergic child will accidentally ingest a problematic food and trigger a life-threatening allergic reaction called anaphylaxis. According to the Centers for Disease Control and Prevention, the prevalence of food allergies increased approximately 50 percent between 1997 and 2011 among U.S. children aged 17 and younger. Currently, there is no way to predict one's risk for severe allergic reactions, and the only approved treatment methods for food allergies are avoidance, and administration of the drug epinephrine to stop a reaction should one occur.
At the Jaffe Food Allergy Institute, we are working to change that through research focused on developing more accurate diagnostic methods and better treatments, as well as preventions for food allergies. It is an exciting and promising time for food allergy research. Below is a glimpse of just some of our research aimed at improving treatment strategies:
Baked Egg and Milk Studies
The standard practice for managing egg and milk allergies has been to pull all forms of these foods from a child's diet. Recent studies have shifted our thinking about this treatment approach. Our research on milk and egg allergies previously showed that the majority of children with these allergies could tolerate products containing baked eggs and milk, such as muffins and cookies, because of the way heat changes the allergenic proteins. We also found that including baked milk or eggs in the diet speeds up the development of tolerance to regular egg or milk, compared to strict avoidance. We are now further studying the mechanisms responsible for these results, with the hope that our answers could dramatically change children's diet restrictions, while shortening the duration of their allergies to regular milk and egg.
Our own research has shown that the prevalence of peanut allergy alone tripled among children between 1997 and 2008, with more than 1 million kids now affected. While children often outgrow allergies to some foods, such as egg, milk, wheat, and soy, allergies to peanuts and tree nuts usually persist. We are currently studying whether providing young peanut-allergic children with an experimental treatment of oral immunotherapy (OIT) will eventually eliminate their peanut allergy.
In OIT, we give a tiny amount of peanut flour periodically and then slowly increase the amount to determine the maintenance dose needed to desensitize the child to peanuts. It's similar to what we do with allergy shots for pollen allergies, except this is a very small amount of the allergen given by mouth. OIT does seem to provide good protection for accidental ingestion of peanuts, but the downsides include a significant number of adverse reactions that occur before the maintenance dose is found, and the requirement for therapy to continue long-term to remain effective.
We are also looking at sublingual immunotherapy (SLIT). This is where we give children a small amount of peanut extract to hold in their mouth. The cells of the mouth take up some of the peanut protein, causing some desensitization to occur. Our findings so far are consistent with what other researchers have seen, in that SLIT does afford some protection for food allergies, but not to the degree that we're seeing in OIT. The big benefit is a significantly lower amount of adverse reactions. We are currently focusing on how to make this therapy more effective at providing a higher level of protection on par with OIT.
Another method we're researching is epicutaneous therapy to see if an experimental skin patch reduces allergic reactions to peanuts in children. In this study, for which I am the primary investigator, the child wears a small skin patch, similar to a little circular Band-Aid, which has a small amount of peanut protein in the center. Older children wear the patch on the inside of their arm, while younger children wear it on their back, and the patch is changed daily.
A very small amount of the peanut protein permeates the outer layer of skin, where special immune cells ingest it and make their way to local lymph nodes. Here, they activate a type of regulatory immune cell, which dampens the immune system's response to the peanut protein. In our research, we have seen virtually no systemic reactions in the children participating in this clinical trial, and we hope this therapy will prove to be a more permanent way to turn off an allergic reaction.
Chinese Herbal Therapy
Finally, we are about to start a human clinical trial of an herbal product designed for use as an investigational drug for children with multiple food allergies, a condition that can be particularly challenging when it comes to dietary restrictions. In preclinical studies, this herbal formula, which is derived from ingredients used in traditional Chinese medicine, proved extremely effective in turning off the allergic response in a mouse model of peanut allergy.
Research conducted over the past few years, and now underway at our institution and others around the country, has generated promising developments in diagnosing and treating food allergies. I am optimistic that in a not-too-distant future, parents will be able to send their food-allergic child off to that party, with the confidence that he or she will return home safe and sound.