When your doctor suspected your baby had cow’s milk allergy,
it’s most likely that they suggested you manage your baby’s
allergy by eliminating cow’s milk protein from their diet to
see whether their symptoms improved.
For breast-fed babies: because cow’s milk
protein can be passed from mother to baby in breast milk,
breastfeeding mums may have been asked to completely remove
milk products from their own diets for around 4 weeks. You
shouldn’t stop breastfeeding because breast milk provides the
best nutrition for your baby.
For formula-fed babies: an elimination diet
involved switching to a formula that is hypoallergenic,
meaning it has been specially designed to not cause allergic
reactions in most children with cow’s milk allergy.
Hypoallergenic formulas for infants with cow's milk allergy
include extensively hydrolysed formulas and amino acid-based
formulas.
After cow’s milk protein was eliminated from your baby’s diet
and when symptoms had improved, your doctor may have requested
an oral food challenge, which involved feeding your baby a
very small amount of a milk-based product and carefully
monitoring for any signs of allergic reactions. This process
will normally take place at a doctor’s surgery or hospital
clinic, or your doctor may have asked you to gradually
reintroduce routine cow’s milk formula into your baby’s diet
while you noted any reactions or behavioural changes. You
should only introduce your baby to foods made with cow’s milk
while under medical supervision.
Occasionally, a doctor may have requested a cow’s milk protein
allergy test to support the diagnosis of cow’s milk allergy —
this will either have tested the skin or blood. Skin tests
involve exposing a small area of your baby’s arm or back to
cow’s milk protein, and then gently pricking the skin so the
liquid is absorbed. If the site turned red or swelled in about
20 minutes while you were at the surgery or clinic, this would
have indicated sensitisation. With a blood test, a sample of
your baby’s blood would have been taken by your doctor and
sent to a laboratory to measure the amount of antibodies that
reacted to cow’s milk protein.
The final diagnosis of cow’s milk allergy will have depended
on the interpretation of the results in the context of
clinical history.