Omelettes, meringues and pasta could one-day be back on the menu for some people with egg allergies after they are treated with the very food they are allergic to, say US researchers.
The only option for patients is to completely avoid foods containing egg.
A study on 55 children showed some were able to eat egg after minuscule amounts were gradually added to their diets.
However, the treatment is still experimental and doctors say it should not be tried at home.
Egg allergies are one of the most common allergies and are thought to affect up to 2.5% of children.
Gradually introducing the food which causes an allergic reaction has been successful in other foods such as such as peanuts.
Parents were given powdered egg to mix into their children’s food, building up to about a third of an egg every day.
The findings, presented in the New England Journal of Medicine, report that after 22 months of egg therapy, 75% of the children were able to eat the equivalent of two eggs without reacting.
The children were tested again after at least a month of no longer having the daily egg treatment. Of these, 28% could still eat egg without reacting and were considered allergy-free.
One of the researchers Dr Wesley Burks, from the University of North Carolina School of Medicine, said: “This study gives us hope that we’re closer to developing a treatment.
“Almost a third of the children had a permanent change and were no longer egg-allergic.”
Dr Stacie Jones, from University of Arkansas, said: “Reducing these kids’ allergic response to egg also lessened parental anxiety over how their children might react if accidentally exposed to egg at school or at someone else’s house.”
However, about 15% of children did not finish the treatment, mostly due to allergic reactions.
Lindsey McManus, from the charity Allergy UK, said: “This is a very exciting development into immunotherapy for food allergy.
“Similar to recent trials being carried out into immunotherapy for peanut allergy at Addenbrookes hospital, the results are very promising.
“It is however very early days and more research will be needed before this is used as a regular form of treatment. We would echo the warning in the report that this should never be tried at home due to the risk of serious allergic reactions.”
By James Gallagher
Health and science reporter, BBC News