Cow’s milk allergy is the most common allergy among infants and young children. A milk allergy, like every allergy, is when your immune system mistakenly identifies one or both of these proteins as harmful.  When you ingest these proteins, your immune system responds and releases histamines, which then cause your allergic symptoms.

Between 2–3% of children younger than age 3 are allergic to milk. Nearly all infants who develop an allergy to milk do so in the first year of their life, but about 80% are likely to outgrow their milk allergy. But this research also suggests that children are outgrowing their milk allergy more slowly than before, with many children still allergic beyond age 5.

Since the majority of children do outgrow their milk allergy, periodic re-evaluation, including testing, is recommended.

However, children who have high levels of cow’s milk antibodies in their blood are most likely to have a milk allergy for life. A simple blood test that measures these antibodies can help your healthcare professional determine whether your child is likely to outgrow their milk allergy.