Progress Against Peanut Allergies

Egg Allergies Studied

"No one should try this at home," Nash cautions. The concept is still in the research phases, and Nash says it's difficult to say when allergists might begin adopting the practice.

Parents in the study were told to contact the center if they suspected reactions; most reactions occurred in the clinic, not at home, Nash says.

More research is needed, he says, to prove the concept safe and effective.

Similar research is being done with egg immunotherapy. Wesley Burks, MD, another author of the peanut immunotherapy study, has done a similar study on egg allergies, Nash says.

The Remission Question

When parents find out their child is allergic to peanuts, they always ask the same question, says Katie Allen, MD, PhD: "Are they going to be one of the 20% who grow out of it?"

Allen is a pediatric gastroenterologist and allergist at the Murdoch Children's Research Institute at the Royal Children's Hospital in Melbourne, Australia.

Until recently, doctors could only guess.

Now, Allen has found some good predictors by looking at skin prick test results.

The Skin Prick Test

In this test, commonly used by allergists, the skin is pricked and a tiny amount of the allergen is dropped onto the skin.

If the person is allergic to the substance, the body's allergic antibody, immunoglobulin E (IgE), is triggered and a chain reaction is set off, resulting in the patch of pricked skin becoming red and swollen.

This raised bump or small hive is called a wheal, and its size is known to give clues about allergies, Allen tells WebMD.

It's well-known by allergists, she says, that "kids who are 12 months old and have a skin prick with a wheal that is more than 4 millimeters means they are more than likely to have a reaction [if they eat the food they're suspected of being allergic to]."

The Remission Study

Allen and her colleagues followed 267 children with peanut allergies, some for years, to see if the size of the wheal over time could predict remission.

The children entered the study at an average age of 14 months -- the time when most infants first show peanut sensitivity, Allen says.

"We looked at the size of the skin prick wheal and followed them," Allen says. Once the size of the wheal that came after a prick fell sufficiently, the scientists would give a food challenge to see if the child had outgrown the allergy.

"We found that 20% of them outgrew it by 5 years of age,'' Allen says.

"We found the best predictor of remission was a falling skin prick test ... every year the reaction got a little smaller," she says.

The size of the wheal when children are younger can predict remission, too, Allen says.