For people living with a peanut allergy, the innocent-looking legume might as well be cyanide: Even trace amounts left over from a shared food preparation space can lead to a dangerous swelling of the airway. This kind of selective toxicity has led to a rash of well-meaning reactions over the years, from schools inspecting lunch boxes for peanut contamination to one Massachusetts school even evacuating a bus because a single peanut had been left on the floor.

But the day may be coming when both the peanut-allergic and the non-responders alike can breathe more easily. Gizmodo reports that a skin patch to treat the allergy just finished the first stage of a highly promising clinical trial.

Dubbed the Viaskin Peanut Patch, the small disc is placed on the arm or between the shoulder blades and delivers micro-doses of peanut protein. Like a vaccine, the idea is to expose the wearer’s immune system to small amounts of the allergen so it can develop a reasonable tolerance.

The first part of the study, which just concluded, gave 74 volunteers aged 4 to 25 with an existing peanut allergy a patch with a high concentration (250 mg), a low concentration (100 mg), or a placebo with no peanut protein at all. A new disc was applied every day for a year, with the subjects returning for a follow-up. Nearly half experienced increased tolerance to peanut exposure, with children aged 4 to 11 seeing the largest amount of improvement. Subjects who responded to treatment could consume at least 10 times the amount of peanut protein that they could prior to the trial.

The Viaskin is not necessarily intended to allow the wearer to enjoy peanuts on a whim, but it may significantly reduce the chances of having a severe allergic reaction to accidental exposures. DBV Technologies hopes to continue the study in pursuit of eventual Food and Drug Administration approval, with an eye on producing similar treatments for those with milk and egg allergies.
 
[h/t Gizmodo]