Cow’s milk is a food which may result in allergy symptoms in sensitised individuals.

Cow’s Milk (Boiled) Allergy Test: Allergen Exposure

Cow’s milk is the most commonly consumed milk, with around 730 million tonnes produced each year, from a total of around 260 million dairy cows worldwide. The United States, India, China and Brazil are the world’s largest exporters of cow’s milk and milk products.

Cow’s milk is processed into a variety of products such as cream, butter, yogurt, kefir, ice cream, and cheese. Modern industrial processes use cow’s milk to produce casein, whey protein, lactose, condensed milk, powdered milk, and many other food-additives and industrial products.

Cow’s milk, cheese and other dairy products are consumed plain or flavoured, and as ingredients in bread, pastry and numerous other dishes such as pancakes and soups.

Cow’s milk is a major cause of adverse reactions in infants, and hidden exposure is common.

Cow’s Milk (Boiled) Allergy Test: Allergen Description

Milk contains more than 40 proteins, and all of them may act as human species antigens.

Casein is a heat-stable allergen present in cow’s milk. Whey proteins such as a-lactalbumin and b-lactoglobulin are altered by heating.

Boiling is known to reduce the allergenicity of the whey proteins but not those of the casein present in cow’s milk. As whey proteins are altered by high temperatures, whey-sensitive people may be able to tolerate evaporated, boiled, or sterilized milk.

Boiled milk or casein can be used to test whether a cow’s milk-sensitive patient is likely to tolerate cooked or baked milk products.

Cow’s Milk (Boiled) Allergy Test: Potential Cross-Reactivity

Cross-reactivity between cow’s milk and milk from related animals exists. This is likely to persist even in boiled cow’s milk, as the a -caseins from cow, goat and sheep, which are unaffected by heat, share more than 85% identical amino acids.

Cow’s Milk (Boiled) Allergy Test: Clinical Experience

Cow’s milk is a major cause of adverse reactions in infants, even when boiled. The prevalence of cow’s milk allergy is approximately 2.5% during the first 3 years of life.

Casein represents 80% of the total bovine milk protein. The major allergens of whey are a-lactalabumin, b-lactoglobulin and BSA. Boiling is known to reduce the allergenicity of the whey proteins but not casein.

Symptoms in infants are usually gastrointestinal and dermatological, with dermatitis often appearing early. Cutaneous symptoms decrease while respiratory and GI symptoms increase with age.

A study of adults with cow’s milk and cheese allergy showed that the majority of the patients were women with symptoms involving the respiratory tract or the skin. Many of them suffered their first symptoms in relation to pregnancy, and most of them remained monosensitised to cow’s milk proteins, primarily casein, which is not affected by boiling.

Very low amounts of cow’s milk protein may elicit an adverse response, even after boiling.

Other reactions

Because boiled cow’s milk still contains lactose, it should be avoided by those who are lactose intolerant.