Experimental treatment for peanut allergy increases anaphylaxis risk, study finds

(CNN)An experimental treatment for peanut allergy may actually multiply someone's risk for serious allergic reactions -- much like the ones it aims to prevent, according to a new analysis.

The paper, published Thursday in the Lancet, found that people taking oral immunotherapy -- microdoses of peanut allergen meant to partly desensitize patients over time -- paradoxically had three times the rate of anaphylaxis compared with those taking a placebo. That risk jumped from 7.1% to 22.2%, based on an analysis of more than 1,000 patients across 12 trials. There were no deaths in any of the trials.
Those taking the treatment also reported more epinephrine use and saw roughly double the rate of other kinds of allergic reactions, the study showed. These findings were attributable to the treatment itself, not accidental exposures to foods, according to the authors.
"There have been so many studies coming out about oral immunotherapy for peanut, there's sometimes conflicting information out there about its effectiveness and reliability," said study author and internal medicine physician Dr. Derek Chu, now a final-year fellow in clinical immunology and allergy at McMaster University in Ontario.