Allergy to Cow’s Milk: Test Your Knowledge

Cow’s milk is one of the nine foods listed by Health Canada, which are responsible for over 90% of severe allergic reactions. Do you know about milk allergies?

1. Milk allergy only occurs in infants. TRUE or FALSE

FALSE. Cow’s milk is one of the most common food allergens. It is true that milk allergy often develops during the first year of life. However, it also affects older children, and sometimes adults. Two to four percent (2–4%) of young children have a cow’s milk allergy, while fewer than 0.5% of adults are affected by this allergy.

2. Once you are allergic to milk, you are always allergic to milk! TRUE or FALSE

FALSE. In most cases, milk allergy vanishes over the years. Indeed, approximately 50% of children who have been diagnosed with a cow’s milk allergy develop tolerance by the age of 1 year, more than 75% by the age of 3 and more than 90% by the age of 6 (5, 6). However, in some people, milk allergy can persist into adulthood. Note that the word “tolerance” is used here in its medical sense, i.e., to endure without signs or symptoms of an allergic reaction, and not the fact of enduring something unpleasant.

Many children with a cow’s milk allergy tolerate cow’s milk in baked goods (the product must be thoroughly heated and fully cooked throughout) (2). Young children who are allergic to fresh milk, but can eat cooked milk without reacting, could be more likely to lose their milk allergy. This could also happen faster than for children who react to cooked milk (7).

*Before integrating fresh or cooked milk, or milk-containing ingredients and foods into the diet of a person allergic to dairy, it is imperative to discuss it with your healthcare professional or allergist.

3. A person with a milk allergy can consume lactose-free milk. TRUE or FALSE

FALSE. Lactose-free dairy products only reduce the symptoms of lactose intolerance. They are not suitable for a milk allergy. Lactose is a sugar found naturally in milk. The process of making lactose-free milk splits the lactose molecule into two other types of sugar, making it easier to digest for people with an intolerance.

A cow’s milk allergy occurs when the immune system overreacts to a protein contained in cow’s milk and cow’s milk-based products, such as yogurt, cream or cheese. Lactose-free milk contains cow’s milk protein, so it is not suitable for someone with a milk allergy.

4. Non-breastfed infants with a cow’s milk allergy can only consume amino acid-based infant formula. TRUE or FALSE

FALSE. Although an amino acid-based formula is necessary for some infants, more than 90% of children with a cow’s milk protein allergy tolerate, without sign or symptom of an allergic reaction, an extensively hydrolyzed infant formula (8).

An extensively hydrolyzed formula is recommended as the first-line treatment for cow’s milk allergy in infants by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the World Allergy Organization (WAO) (8). The severity of symptoms, preference of the allergic child’s parent, and efficacy and cost of the formula should also be taken into account when choosing the preparation (8).

Amino acid formulas are hypoallergenic, and are indicated in those rare cases where an extensively hydrolyzed formula does not produce an optimal response or causes an allergic reaction in infants with cow’s milk allergy (8).

Note that the formulas that are partially hydrolyzed should not be used to treat cow’s milk allergy.

*Talk to your healthcare provider or allergist about the most appropriate infant formula for your child.