Parents frequently ask whether their child’s food allergy will be outgrown, or will it persist. This article is aimed at providing you with a general understanding of this subject, although you should always be guided by your allergy specialist with regard to your own child’s particular case. We concentrate on ‘immediate onset’ food allergy – where the symptoms occur, in most cases, within seconds or minutes of contact with the culprit food.
Most children with food allergy outgrow their allergy during childhood. This is particularly true for allergy to cow’s milk, wheat and hen’s egg – although for a few, allergies to any of these foods can persist.
Some food allergies are less likely to be outgrown. This is particularly true for those who are allergic to peanuts, tree nuts (such as walnuts, cashews and Brazils), fish and shellfish. With sensible day-to-day management, risks can be greatly diminished and we would advise you to read our individual fact sheets on these allergies. Links are provided at the end of this article.
Peanut allergy: Until 1998, doctors believed peanut allergy persisted for life. But evidence emerged suggesting that where it developed early in life, peanut allergy in children could be outgrown.
It is believed that around 20 per cent of children with peanut allergy will outgrow it.
Tree nut allergy: American research in 2005 evaluated 278 children with tree nut allergy and concluded that only nine per cent outgrew their allergy. This did include some children who had had severe reactions.
Most children who outgrow either peanut or tree nut allergy will have done so by the age of six.
Hen’s egg allergy: Studies have shown that many children with egg allergy outgrow it, but there are differences of opinion about the age at which this occurs. A 2007 American study concluded that four per cent of the children taking part in the research outgrew their egg allergy by age four, 12 per cent by age six, 37 per cent by age ten and 68 per cent by age 16. Other studies have suggested that a larger number may outgrow their egg allergy before they reach their teens.
Milk allergy: Recent evidence suggests that about half of children with an immediate form of milk allergy will outgrow it by five years of age. After that it can still be outgrown but a few children will carry their allergy into adult life.
There are other conditions where cow’s milk triggers adverse symptoms, including delayed cow’s milk allergy and lactose intolerance. If you or your child suffers from any of these, it is advisable to get a doctor’s opinion on whether the condition is likely to be outgrown.
Fish and shellfish allergy: As stated above, for people allergic to fish or shellfish, it is likely this will persist for life. With sensible day-to-day management, risks can be greatly diminished.
Wheat allergy: The natural history of true wheat allergy – which occurs when the body’s immune system reacts to one or more of the proteins found in wheat – has not been well studied. However, clinical experience recognises that it is typically mostly outgrown in the pre-school years.
Sesame allergy: Sesame allergy tends to appear early in life and, according to at least one study, persists in 80 per cent of the cases. Those who outgrow it are likely to have done so by the age of around six.
Reviewing children’s food allergies
If you believe your child may have outgrown their food allergy, you are advised to seek medical advice on this. Your GP can refer you to an allergy clinic, where an oral challenge may be given to verify whether the allergy has been outgrown. Such challenge testing involves the patient eating small amounts of the culprit food, gradually building up the quantity until it can be shown that the patient is not allergic. This must be strictly controlled at an allergy clinic.
If the test is negative, your child is no longer allergic. There is a very strong chance that the allergy will not recur, although this does happen in a very small minority of cases. If your child has been carrying adrenaline, the question of whether they should play safe and still carry adrenaline must be discussed with the doctor overseeing the challenge. Some doctors advise that injectors should continue to be carried for a further limited period.
Finally there is the question of whether the child who is no longer allergic to a food should begin eating that food frequently. This will need to be discussed with your doctor, who will usually advise continuing regular consumption to ensure the tolerance to the food is maintained.
Read more about peanut allergy and tree nut allergy
Read more about egg allergy
Read more about milk allergy
Read more about wheat allergy
Read more about sesame allergy
This article has been peer reviewed by Dr Trevor Brown, Consultant Paediatric Allergist, Ulster Hospital, Belfast.
All the information we produce is evidence based or follows expert opinion and is checked by our Clinical and research reviewers. If you wish to know the sources we used in producing any of our information products, please let us know, and we will gladly supply details.