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: A recent study from the Isle of Wight followed children with peanut allergy up over 10 years and found over this year period of time, 10% outgrew their allergy. It is thought that by adulthood, around 20% would have outgrown their allergy.
Tree nut allergy: A systematic review assessing all published studies from 2020, found that between 9-14% of children with tree nut allergy outgrew this allergy. This did include some children who had had severe reactions.
The age by which the children outgrew both peanut and tree nut allergy varied significantly and it is therefore important for your child to have a regular review with the allergy specialist.
Hen’s egg allergy: Studies have shown that many children with egg allergy outgrow it, but there are differences in age of achieving tolerance depending on where the research has been published. This is most probably related to the type and severity of patients enrolled in studies. The Europrevall study, the largest multinational study on food allergy, followed egg allergic children up until 2 years of age and found that half outgrew their allergy within 1 year of diagnosis. A recent study (2020) has been less optimistic with half of children outgrowing by 5 years of age. 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.
Milk allergy: Although it is thought that the prognosis for outgrowing a milk allergy remains very positive, data does indicate a variation in age at which this happens. In the last 10 years a shift towards tolerating milk at a later age has been noted. In the CoFAR and Europrevall studies, 53% and 57% outgrew their allergy by 2 years and 1 year of age respectively. However, as with the egg allergy, some studies have shown a slower rate of achieving tolerance, with one reporting resolution of cow’s milk allergy at age 4, 8, 12, and 16 years of 19%, 42%, 64%, and 79%, respectively
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: True wheat allergy occurs when the body’s immune system reacts to one or more of the proteins found in wheat. There have been a limited number of studies on when wheat allergy is outgrown. A study from 2017 found that 45% of wheat allergic children outgrew their allergy by 5 years of age.
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
As children can outgrow their allergy, it is important to have regular follow-up appointments with your allergy specialist. If you believe your child may have outgrown their food allergy and have no appointment with an allergy specialist, 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 and should not be tried at home.
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, if your child has outgrown their food allergy, the question you may ask is: should they eat the food or avoid it? There is strong evidence that you should include the food regularly in your child’s diet to ensure the tolerance to the food is maintained and this view is widely supported by the medical community. It can happen that your child does not like the food or the format of the food challenged, in which case it is advisable to discuss this with your child’s dietitian to find foods that are acceptable to your child that contain the tolerated allergen.
Read more about peanut allergy.
Read more about 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. Rosan Meyer, Paediatric Research Dietitian, Imperial College, London.
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.
Published: September 2020
Review date: September 2023