Q: Hi Doctors. Talking about cow’s milk allergy, I have been giving my 7 month old baby a HA (hypoallergenic) milk (since he was 4 m/o) because his paeds was certain he has cow’s milk allergy.I was wondering when should I switch to a normal formula since he is now free from rashes. (Abby)
A: Dear Abby, thank you for your question. It is a dilemma to parents as to the timing of reintroducing back cows milk if their child is allergic to cow’s milk. However before I answer your question I would like to explain a little more about cows milk allergy.
Almost anyone can be allergic to cows milk, however it is more common in infants (about 2% – 3% of infants). It occurs when the body “mistakenly recognizes milk protein” as a harmful protein to the body – hence the “body tries to fights it off”.
Problems may occur even with exclusive breast feeding if mother ingests cow’s milk. Most infants who are allergic to cow’s milk also react to goat’s milk, sheep’s milk as well as soya milk. Infants who are breastfed have a lower risk of developing a milk allergy than those who are formula fed. But researchers don’t fully understand why some develop a milk allergy and others don’t, though it is believed that in many cases, the allergy is genetic.
When the “body tries to fight it off” it may appear as problems on the skin – which is how your baby presented. However it can also present as tummy upsets, feeding problems, breathing problems and diarrhoea etc. These problems start either very quickly after feeding or within days (7-10 days) or even weeks after introducing cows milk fomula. It is important for your baby to be assessed by a paediatrician to rule out other health conditions as it can present in many ways.
In some countries a skin allergy testing is done to in addition to a stool test and a blood test. Some centers also measure the Ig E which indicates if your child is allergic. Even if these tests are not available your childs paediatrician would be able to acertain if your child has cow milk allergy from history and clinical examination.
Once confirmed, your doctor would advise you to eliminate diary products from your diet if you are breast feeding or if needed to start your baby on hypoallergenic formula /amino acid formula accordingly.
Abby, your concern was when to switch to normal formula milk. Traditionally, it was thought cow’s milk allergy goes away on its own by the time a child is 1 to 2 years old and some might not outgrow it until adolescence.
However there are 2 recent studies :-
1st study – shows that milk tolerance at 1 year was 30% and 2 years old 54%, 3 years old 70%. (by Carroccio et all on study on Italian infants)
2nd study – Difference in milk tolerance related to Ig E ( Vanto et al on study on Finnish infants)Non IgE mediated: showed milk tolerance at 2 years 64%, 3 years 92% and 4 years 96% IgE mediated: showed milk tolerance at 2 years 31%, 3 years 53% and 4 years 63%
Hence taken together, these results suggest that cow’s milk protein can be reintroduced in trial fashion at 1 year of age in children with non–IgE-mediated allergy, while children suspected of IgE-mediated allergy should not be exposed to cow’s milk for longer time periods, with the length of time guided by allergy testing.
( answered by Dr Charlotte Jane Joseph )