Researchers have developed an alternative method to desensitize young children with peanut allergies to the food. Sublingual immunotherapy is safer and easier to administer than current treatments, research has found, potentially offering another way to curb this potentially fatal allergy.
Peanut allergies usually develop early in life and rarely outgrow them. Peanuts are the food most likely to cause anaphylactic shock and death, causing children and their parents to experience the anxiety and social isolation that often accompany life-threatening allergies.
Oral immunotherapy (OIT) has been extensively studied as a method of inducing peanut desensitization in children and adolescents, but may cause adverse effects. So researchers at the University of North Carolina (UNC) School of Health have developed a sublingual immunotherapy that can be safely used in young children with peanut allergies.
"Based on our previous studies in older children, we were optimistic that peanut SLIT (sublingual immunotherapy) would have similar therapeutic effects in young children," said Edwin Kim, first and corresponding author of the study. "However, what we found was even better. The levels of desensitization we saw were higher than expected and comparable to what we typically think can only be achieved with oral immunotherapy."
Oral immunotherapy involves mixing peanut powder with another food and eating it, while oral immunotherapy involves adding a small amount of peanut protein to a liquid and administering it under the tongue. Researchers recruited 50 children ages 1 to 4 with peanut allergy, half of whom received 4 mg of peanut oral solution and the other half received a placebo. The study's primary endpoint was desensitization, assessed by food challenge three years after treatment.
Researchers found that almost 80 percent of children who received SLIT were able to tolerate a 15-peanut food challenge without developing allergy symptoms after completing treatment. Given that typical peanut allergic reactions are caused by one or fewer peanuts, these results imply strong protection against peanut exposure, the researchers said.
They also found that 63% of children maintained protection from peanut allergy three months after stopping treatment, indicating remission. The highest response rates were among children aged one to two (58%), followed by children aged two to three (33%) and three to four (43%), suggesting that early intervention may be important.
There are reports that participants in peanut SLIT will experience symptoms of itchy throat, which is similar to the results of the environmental allergen SLIT study, but these symptoms are self-limiting, can resolve on their own, and will not lead to more severe reactions. Other reactions - skin, gastrointestinal and respiratory tract reactions - were similar between the treatment and placebo groups.
The researchers say their findings suggest SLIT is safer and simpler to administer than peanut OIT.
"Peanut OIT is now commercially available and is being used by an increasing number of allergists, however, we quickly discovered that in addition to the known risk of allergic reactions, the practical implementation of OIT is very difficult for many families," said Kim. "Peanut SLIT may be a good option to consider as it may be able to provide a comparable level of protection while being safe and easier to administer."
The study was published in the Journal of Allergy and Clinical Immunology.