Ask the Allergist: Evaluating the Potential of Oral Immunotherapy, Peanut Patch
Q: I have a son with peanut allergies. I’ve heard about new treatments for food allergies that are on the horizon. How do oral immunotherapy and peanut patch therapy work and what’s their potential in terms of effectively treating food allergy?
Julie Wang, MD: Right now it is a very exciting time in the field of food allergy because there are a lot of studies looking at these potential treatments.
Oral immunotherapy involves slowly increasing a patient’s exposure to the food allergen in question – for your son it would be peanut – starting at very low doses and slowly increasing up to a target dose.
What researchers have found is that by building up peanut exposure slowly, we can desensitize the child to pretty high doses of peanut protein. There is a range of peanut doses different studies have targeted. Some studies aim for protection from accidental exposure, such as when a peanut-allergic child inadvertently eats one peanut. Other studies aim to go much higher, where the child can actually ingest multiple peanuts and experience minimal or no reactions.
The peanut patch is a different approach in that the application of the allergen dose is via the skin. There are immune cells in the skin and we believe that by exposing those skin allergy cells we can desensitize them and make the body more accepting to peanut.
Rather than an escalating dose over time, the peanut patch is one dose and it’s applied on a daily basis. Recent studies have shown it has been able to achieve certain levels of desensitization – not quite as robust as what is seen in oral immunotherapy, but some protection nonetheless, especially for accidental exposures – which may be sufficient in terms of what parents want for their child.
Oral immunotherapy and the peanut patch are not FDA approved — meaning they are not currently available to the general public. But keep an eye out for these treatments and talk with a board-certified allergist if you think they might help.
Q: Are researchers looking for a cure or for protection against food allergens?
Dr. Wang: This is a common question. Some are looking for a cure. Ultimately a cure would be the best-case scenario for all of us, but we’re not quite there yet. In the meantime, there are patients and families who would be quite satisfied with protection from accidental food allergen exposures on a daily basis.
For example, there are ongoing studies examining what happens when a patient discontinues oral immunotherapy or peanut patch treatment for a period of time. Is the protection continued or not?
Q: What are side effects or concerns about these treatments parents should be aware of?
Dr. Wang: In any medical therapy, we have to consider not only what the effectiveness might be but also what the safety profile would be, and that’s an important factor when considering what treatment options a patient might consider.
For oral immunotherapy, side effects are fairly common. Some are mild and can include skin rashes and stomach discomfort, while others are serious and may require the use of an epinephrine auto-injector. Oral immunotherapy side effects often happen during the low-dose phase when patients first start the build-up process. Side effects do tend to become less frequent as treatment continues.
We have seen people drop out of oral immunotherapy studies because the side effects are intolerable, so this is an important factor to consider.
While the overall effectiveness of the peanut patch is not quite as robust as compared to oral immunotherapy, there is a better safety profile. Many people do experience some side effects such as skin rashes, but those are usually localized to where the patch is administered on the skin and symptoms are generally very mild.
Since there are currently no FDA-approved oral immunotherapy and peanut patch treatments for peanut allergy, a better understanding of the risk-versus-benefit ratios will ultimately guide healthcare providers in determining the best options for your child once these treatments are available.
Julie Wang, MD, FACAAI, is associate professor of pediatrics, allergy and immunology at Mount Sinai Hospital in New York City. She is also a fellow with the American College of Allergy, Asthma and Immunology.
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