With a warning not to try exposure therapy at home, researchers conducting a study on children with peanut allergies (STOP II trial) discovered that exposing allergic individuals to larger and larger amounts of peanuts over time could build up a tolerance to the nut. The results of the oral immunotherapy (OIT) study were published in the journal The Lancet.
Food allergies including peanuts allergies have been on the rise in recent years. Peanut allergies can cause a severe and potentially fatal allergic reaction called anaphylaxis. Until recently, the only way to avoid an allergic reaction due to a peanut allergy was to avoid the trigger, i.e., avoid exposure to peanuts.
OIT is a technique for treating allergies that involves exposing an individual to an allergen in increasing doses over a period of time. The technique induces the immune system to tolerate a food, with the goal of being able to consume the food without experiencing an allergic reaction. Because there is a risk of anaphylaxis, OIT should be administered only under the supervision and guidance of a trained and certified professional.
In the present study, researchers at the Cambridge University Hospitals in the United Kingdom followed 99 children between the ages of 7 and 16 years old with peanut allergies. Half of the children received 26 weeks of OIT using gradually increasing doses of peanut protein. The other half followed a standard treatment plan which included avoiding exposure to peanuts.
After six months, all the children took part in a double-blind placebo-controlled food challenge in which the children gradually consumed increasing amounts of peanut protein.
Of the children receiving the OIT, 62 percent passed the food challenge, tolerating daily dose of 1,400 milligrams of peanut protein, which equates to roughly 10 peanuts. None of the control group passed the food challenge.
After the first test, a second trial was performed in which all the children received OIT. At the end of the second, 54 percent of the children passed the food challenge.
Additionally, after the second trial, 84 to 91 percent of the children could safely consume 800 milligrams of peanut protein, or approximately five peanuts.
Comments study leader Dr. Andrew Clark:
“This treatment allowed children with all severities of peanut allergy to eat large quantities of peanuts, well above the levels found in contaminated snacks and meals, freeing them and their parents from the fear of a potentially life-threatening allergic reaction.”
The researchers do note that approximately one-fifth of the children experienced adverse events as a result of the OIT. One participant who withdrew from the study required adrenaline to treat allergic symptoms after only two doses of OIT.
The researchers also state that OIT should be performed only by medical professionals but that the results of the study are an important advance in peanut allergy research. Additional studies are also needed on the efficacy of OIT for the treatment of peanut allergies.
Cautions co-author Dr. Pamela Ewan:
“However, further studies in wider populations are needed. It is important to note that OIT is not a treatment people should try on their own and should only be done by medical professionals in specialist settings.”
Regardless, the results of the present study indicate that treatment beyond avoidance may be possible for individuals with peanut allergies.
References
Assessing the efficacy of oral immunotherapy for the desensitisation of peanut allergy in children (STOP II): a phase 2 randomised controlled trial: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2813%2962301-6/abstract#aff1
Exposure to peanuts builds immunity in allergic children: http://www.medicalnewstoday.com/articles/271918.php
Image Credits
Some Salted Peanuts: http://www.freeimages.com/photo/844754
