A child has outgrown an allergy when their immune system stops reacting to the offending food, in this case, cow’s milk.

Yes, evidence suggests that allergies are more common in childhood. Cow's Milk Allergy has a good prognosis and most children with milk allergy will outgrow it by the time they reach adulthood ¹. 

Generally, children with delayed milk allergy (non-IgE mediated) are likely to outgrow their allergy sooner than those with immediate symptoms (IgE mediated)¹. 

Young children that tolerate baked milk in their diet early on, and have less severe reactions, are more likely to outgrow their allergy in comparison with children who cannot tolerate any forms of milk and who have more severe reactions.

Those with multiple allergies are likely to take longer to outgrow their allergy ¹, as are those with co-sensitisation to beef, eggs, wheat and/or soy ². 

For those with an IgE mediated milk allergy, it is more likely to be persistent in those with asthma and/or allergic rhinitis ¹, those with a strong family history², and children with severe atopic dermatitis (AD) more so than those with mild AD².

Some children may tolerate cow’s milk in their diet but never fully outgrow the allergy. This means that the allergy has not completely resolved, and the child may retain some allergy.  These children may not tolerate cow’s milk during periods of illness or the Cow’s Milk Allergy may “reappear” in adulthood, for example during pregnancy or during breastfeeding³.

The majority of children outgrow their Cow's Milk Allergy by the age of five, and around half by the age of one year. If clinically appropriate, it may therefore be worth trying the infant at around one year old (or sooner for some) with the introduction of milk-containing foods, but only if they have been milk-free for at least 6 months ⁴. Read about the introduction of milk ladders.

According to BSACI (British Society for Allergy and Clinical Immunology), studies from before 2005 showed that children had an 80-90% chance of outgrowing Cow’s Milk Allergy by school age.  Unfortunately, studies since then have shown a smaller percentage but it is not known if this is because allergies are persisting for longer or because methodology in studies have changed ¹.

One way that parents find out their child has outgrown their allergy is when their child accidently has a food containing milk or dairy. Young children are naturally curious and will take food from their siblings and/or peers. 

Another accidental exposure can happen when a product’s ingredients change, and the parent hasn’t realised. There is no obligation for companies to state on the front of packaging that ingredients have changed, and parents may miss a change in the ingredients on the back of the packaging.

Signs that a child is outgrowing their allergy include: 

• no reaction on ingestion of a previously non-tolerated food
• a reduction in symptoms
• a volume of the same food is required to illicit the same symptom severity

Sometimes the parent isn’t aware that their child has had a dairy-containing product.

It’s, therefore, important to have a good knowledge of products or to refer to a Paediatric Registered Dietitian who can be invaluable in unpicking this kind of information.

Those with a Skin Prick Test (SPT) weal size < 5 mm at diagnosis are more likely to have developed tolerance at 4 years (83%), whilst those with a weal size ≥ 5 mm at diagnosis are more likely to have persistent allergy (74%) ¹.

Repeat skin prick tests may show a reduction in size and a paediatric allergist may then deem it relatively safe to start introduction. The introduction may be carried out in hospital (known as a challenge) or very cautiously at home, under close supervision by a specialist allergy dietitian following a very strict protocol. Parents are carefully selected (to ensure they fully understand the risks and procedure), and the child’s medical condition is carefully assessed. This process must never be undertaken by anyone outside a specialist allergy clinic. 

For children with non-IgE milk allergy, there are no such tests.  Tests which are widely advertised and available via the internet, and have no scientific basis include the following: Vega testing, hair analysis, IgG testing, Pulse test, Kinesiology. These do not give any indication of when the best time is to reintroduce.

The only way to test to see if an infant has started to outgrow a non-IgE milk allergy is to try a small amount of milk protein and build up the amounts, gradually. If clinically suitable, this should be started when the infant is around one years of age, although some infants can be started a little sooner if they have been milk-free for at least 6 months. 

A milk ladder is designed to introduce milk gradually, one step at a time. The most used is the iMAP milk ladder. There are other milk ladders available, often produced locally, but this one has been put together by a team of experts and has good evidence behind it. It also considers different cultural backgrounds and different food availability in different countries.

If the milk ladder is not successful, it should be re-tried around 3-6 months. Parents will need support from a healthcare professional to ensure they periodically retry the ladder. Ideally, the family should be supported by a Paediatric Registered Dietitian as they have in-depth knowledge of alternative foods to try (when children refuse foods on the milk ladder), but this depends on local availability.