Egg allergies can be beaten – or at least substantially reduced, research suggests.
As part of the study, children with severe egg allergies were fed tiny amounts of egg protein. Over time, the dose was steadily increased. After 22 months of daily treatment, a significant percentage of the children were essentially cured, while others experienced far less extreme reactions to eggs, according to the findings published this week in The New England Journal of Medicine.
"The idea behind this form of treatment is that the body gradually learns to tolerate exposure to the substance," said one of the researchers, Robert Wood, director of allergy and immunology at the Johns Hopkins Children's Center in Baltimore.
Earlier studies have suggested that this approach – known as oral immunotherapy – may be also useful for treating children with milk and peanut allergies.
In this trial, the researchers divided 55 children, aged 5 to 11, into two groups: 40 were treated with increasingly higher levels of powdered egg whites and 15 were given a placebo of cornstarch. Five of those 40 getting the real egg protein dropped out of the study, largely because of allergic reactions related to treatment.
After 10 months, 22 of the 35 children given the treatment could tolerate five grams of egg-white protein – which is equivalent to half of a large egg. And at the end of 22 months, 30 kids could eat 10 grams – or a whole egg.
The therapy was then stopped for about six weeks. Being able to consume eggs without a reaction after a period of abstinence is considered a true indicator of sustained tolerance – or basically being cured. At the end of the six weeks, 11 kids were still able to tolerate a whole egg.
The fact that the level of tolerance dipped in some patients suggests that treatment may need to be continued on a regular basis.
"The good news is that we do believe this can work," Dr. Wood said. Even if it doesn't provide a complete cure for everyone, the treatment may be able to reduce the severity of allergic reactions in many patients. Egg allergies can be extremely serious and trigger life-threatening anaphylactic shock in some individuals."
About 4 per cent of children develop egg allergies. Some naturally outgrow their food allergy, but for many individuals it can become a lifelong affliction. So a significant reduction in symptoms could provide peace of mind to those who might be inadvertently exposed to egg products when eating out at restaurants or social gatherings.
Dr. Wood cautioned, however, that a lot more research needs to be done before the therapy is ready for the general public. Oral immunotherapy is still considered experimental and should not be attempted outside a research trial. "We do this extremely carefully to try to prevent any severe reactions," he noted.