Therapy Technique Shows Promise for Peanut Allergy Sufferers
Increasing numbers of children are being diagnosed with food allergies, with tree nut and peanut allergies constituting a significant portion. A new NIH-funded study is among the first to evaluate sublingual immunotherapy (SLIT) as a peanut allergy treatment.
According to the Food Allergy and Anaphylaxis Network, as many a 15 million people have food allergies. The Centers for Disease Control and Prevention have found that there has been an 18% increase in the number of food allergy patients between 1997 and 2007. Peanut allergy, in particular, has tripled among children in the same amount of time. While kids may outgrow some types of food allergies, allergy to peanuts is generally lifelong.
Sublingual immunotherapy is an alternative way to treat allergies without injection. An allergist gives a patient small doses of an allergen under the tongue to boost tolerance to the substance and reduce symptoms. While SLIT is widely accepted and used in European, South American, and Asian countries, it is still not an FDA-approved therapy here in the US.
A new study, supported by the National Institutes of Health, has found that SLIT can reduce the allergic response to peanut in adolescents and adults. As one of the first randomized, placebo-controlled studies into the efficacy and safety of SLIT, the study enrolled 40 people aged 12 to 37 years with peanut allergy who were on a peanut-free diet. After an initial food challenge to measure how much peanut powder could be eaten without reaction, half of the participants received 44 weeks of daily therapy, followed by a second food challenge. The remaining 20 patients were given a placebo (inactive ingredient).
Fourteen of the 20 (70%) given peanut SLIT were able to consume at least 10 times more peanut powder than they could at the beginning of the study. Study investigators also observed that SLIT caused only minor side effects, such as itching in the mouth, suggesting that daily therapy is safe.
Although more work is needed, the investigators hope that SLIT could one day help protect people with peanut allergy from experiencing severe allergic reactions in cases of accidental exposure.
"These results are encouraging," said Wesley Burks MD of the University of North Carolina School of Medicine. "The immune response was stronger than we thought it might be, and the side effects of this treatment were relatively small. However, the magnitude of the therapeutic effect was somewhat less than we had anticipated. That's an issue we plan to address in future studies."
Please note: SLIT should only be performed under medical supervision in a carefully monitored clinical trial. It can be deadly to attempt this on your own at home.
DM Fleischer et al. Sublingual immunotherapy for peanut allergy: a randomized, double-blind, placebo-controlled multicenter trial. Journal of Allergy and Clinical Immunology DOI: 10.1016/j.jaci.2012.11.011 (2013).