When you live in fear of you or your child accidentally ingesting peanut crumbs, any hope of undoing severe food allergy is welcome.

A large clinical trial published this week in the Lancet confirms what smaller studies have shown in the past: Oral immunotherapy - swallowing tiny, increasing amounts of peanut over time - has the ability to desensitize allergic individuals to peanuts.

Peanuts are one of the leading causes of food allergy reaction, and 400,000 school-aged children in the United States have this allergy, according to the American College of Allergy, Asthma and Immunology. Symptoms may occur from any contact with the peanut protein, which is why cross-contamination of foods can be very dangerous.

The new results in the Lancet are a "very positive finding" because peanut-allergic people who become able to tolerate peanuts don't have to worry about any accidental exposure or trace amounts of contamination, said Dr. Anna Nowak-Wegrzyn, associate professor of pediatrics at Mount Sinai Hospital in New York, who was not involved in the study.

Still, this is not a cure, she noted. The current thinking is that people who undergo oral immunotherapy need to continue eating peanuts every day in order to maintain tolerance.

Read - New treatment may offer hope for peanut allergy

Previously - Peanut-controlled seating a home run for allergy sufferers