Looking for a way to treat your child's allergy to a certain food? New research shows that feeding your child increasingly higher doses of that very food can eliminate or ease reactions in most cases.
It may sound counter-intuitive, but a study published last week in The New England Journal of Medicine adds to a growing body of evidence that the approach - known as oral immunotherapy - can, over time, condition the immune system to tolerate the food with minimal or no reaction.
The study, conducted at the Johns Hopkins Children's Centre and four other US institutions, looked at egg allergies. Recent, smaller studies conducted at Johns Hopkins and elsewhere have shown that the approach can also be useful in treating children allergic to milk and peanuts.
The researchers say the results are promising but caution that, at present, oral immunotherapy is still considered experimental and should not be used outside a strictly controlled research protocol.
In Hong Kong, an estimated 5 per cent of children have food allergies. Some outgrow them, but for many they are lifelong and require complete avoidance to prevent serious or life-threatening reactions.
In the study, conducted as part of the National Institutes of Health-funded Consortium of Food Allergy Research, 35 of 40 children treated with egg immunotherapy over 32 months experienced improvement. The five children whose condition did not improve dropped out of the study, four because of allergic reactions related to treatment.
Eleven of the 35 eliminated their allergies - they were able to have 10 grams of egg protein (equivalent to a large egg) without any symptoms after the treatment period followed by abstention for four to six weeks. This was considered the true marker of sustained tolerance, the scientists say. A year later, all 11 reported eating eggs and products containing eggs without symptoms as frequently or as infrequently as they chose. The rest of the 35 were able to tolerate higher doses of egg with only mild symptoms.
How much do you know about allergies? Test yourself here with this quiz by the University of Arkansas for Medical Sciences.
1. Which of these body systems causes allergic reactions?
2. An allergen is anything that triggers an allergic or hypersensitive response. Which of these could be an allergen?
c. Nickel jewellery
3. What does the body release to combat allergens?
4. The most severe form of allergic reaction is known as anaphylaxis. What happens?
a. Blood pressure drops
b. Breathing becomes difficult
c. Runny nose develops
Answers: 1. b; 2. all are correct; 3. c; 4. a and b