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

Cow’s Milk 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.

Historically, humans have been unable to properly digest cow’s milk after childhood, as adults do not produce the enzyme lactase, required to break down the lactose in milk. Cow’s milk consumption was therefore limited to curds, cheese and other refined milk products which have reduced levels of lactose.

Several thousand years ago however, a chance mutation emerged resulting in widespread lactase production throughout adulthood in certain, mostly European, populations.

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.

Whole cow’s milk, butter and cream have high levels of saturated fat.

Cow’s Milk 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.

Cow’s Milk Allergy Test: Potential Cross-Reactivity

The presence of shared allergens in milk, meat, and dander from cows has been demonstrated. Sensitivity to cow’s milk does not usually entail sensitivity to beef or inhaled cow dander.

In some cases homologous milk proteins of different species can lead to cross‐reactivity in sensitized/allergic individuals.

Cross-reactivity between cow’s milk and the milk from other mammals such as goat and sheep has been reported. Cross‐reactivity to donkey, mare, and camel milk is rarely observed.

Cow’s Milk Allergy Test: Clinical Experience

Cow’s milk is a major cause of adverse reactions in infants. Cow’s milk-induced asthma is often observed in infants with food hypersensitivity. Asthma has been noted in 7-29% of those sensitive to cow’s milk.

Milk is often described as a cause of rhinoconjunctivitis in young children.

The 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.

Inhaled milk proteins may cause occupational asthma in workers handling powdered proteins.

Very low amounts of cow’s milk protein may elicit an adverse response.

Other reactions

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