Milk allergy is an abnormal immune response by the body to the proteins found in milk (usually cow’s milk) that are normally not elicited by non-allergic individuals. Milk allergy is distinct from lactose intolerance although some symptoms are confusingly similar. 

Mechanism of the allergic reaction

The term allergy is used to describe the immune responses made by the body to foreign proteins found in substances like cow’s milk, followed by the release of chemicals (e.g. histamine, leukotriene) that causes the following manifestations that may begin minutes after ingestion of milk:

Dermatologic

• hives
• urticaria

Gastrointestinal

• abdominal pain
• vomiting
• diarrhea
• colic (babies)

Respiratory

• runny nose, nasal congestion
• cough
• recurrent colds, sinusitis, and ear infections
• wheezing
• may progress to anaphylaxis

On the other hand, the mechanism that causes lactose intolerance is mainly due to the deficiency or absence of lactase, the enzyme that is required to metabolize milk sugar lactose.

Another condition called milk protein intolerance symptoms also resemble milk allergy, however the responses are delayed. The immune system produces an antibody different from IgE-mediated allergic reactions.

What your Doctor can do for you

The majority of cases of milk allergy occur mostly among children, especially infants. It affects between 1 to 7% of children around the globe, but usually disappears after 3 years of age.

The diagnosis will base on the patient’s clinical history if the symptoms appear immediately after intake of small volumes of milk or milk formula. Older children are adults may need to undergo further skin (prick) and blood (RAST) testing as milk may be consumed with other food allergens. The only treatment for milk allergies is nothing more than to avoid cow and goat’s milk and milk formulas. Some products may have hidden traces of milk protein with them. Milk products include, butter, yogurt, cheese, margarine, cream, ice cream, bread, cookies, cakes and pastries, whey, whey powder, casein, and lactic acid. Soy milk is seldom used as a substitute as there are also milk-allergic children who are also allergic to soy milk.

Epinephrine will be prescribed to those who have severe allergic reactions. Minor symptoms are managed by antihistamines.

What you can do

For breastfed infants, lactating mothers should also take part in eliminating milk from her diet as the allergen may be passed through breastmilk. Always read the packaging of food products to determine milk content.

Special infant formulas are widely available now in the market. Adults may consume milk substitutes like rice milk, soya milk, and oat milk.