Cow's milk allergy
Hives after a latte, or an itchy mouth after cheese? Cow's milk allergy is an immune reaction to milk proteins, and it is not the same thing as lactose intolerance. Our test checks for IgE antibodies to cow's milk and seven single milk proteins, as part of 300 allergens and allergen components. It does not test for lactose intolerance.
- Group
- Food
- Also known as
- milk, dairy, casein, whey, beta-lactoglobulin, alpha-lactalbumin
Where you meet it
- Milk, cream, butter, yoghurt, cheese and ice cream
- Bread, biscuits, cakes and chocolate
- Processed meat, sauces, soups and ready meals
- Protein shakes and bars (whey and casein)
- Ingredients such as caseinate, milk powder, lactalbumin and ghee
Milk allergy and lactose intolerance are different things
Milk allergy is the immune system reacting to milk proteins. IgE antibodies drive the fast type, and that is what our test measures.
Lactose intolerance has nothing to do with the immune system. It happens when your gut makes too little lactase, the enzyme that breaks down milk sugar. Unbroken lactose ferments in the gut and causes bloating, wind and loose stools, usually a few hours after dairy. Our test does not measure lactose intolerance, and an IgE result cannot rule it in or out. A doctor can advise on how to check for that.
Casein and whey
Milk protein comes in two main families. Casein makes up about 80% and survives heat well, so it stays intact in baked goods and cheese. Whey proteins, such as beta-lactoglobulin and alpha-lactalbumin, are more sensitive to heat.
Specialists sometimes use this difference to judge which forms of milk someone might tolerate. That is a decision for an allergist, ideally with a supervised challenge, not something to work out at home from a result.
What people commonly report
Fast reactions people report after dairy include itching or tingling in the mouth, hives, swollen lips, vomiting, and in some cases wheezing. These usually start within minutes to two hours. Bloating hours later with no other symptoms points more often to intolerance than to IgE allergy, but only a doctor can tell you which applies.
Swelling of the lips or throat, or trouble breathing, is an emergency. Call 112 (EU) or your local emergency number.
How our test checks milk
The lab measures IgE to a whole cow's milk extract and to seven single milk proteins (molecular components). Goat's, sheep's, mare's and camel's milk are on the same panel. Your lab report gives each a measured value and class, from Negative to Very high. A result shows sensitisation, which is not the same as a clinical allergy. Do not cut out or reintroduce dairy based on the result alone; talk it through with a doctor.
- Whole cow's milk extract
- Caseins: Bos d 8 (whole casein), Bos d 9, Bos d 10, Bos d 11 and Bos d 12
- Whey proteins: Bos d 4 (alpha-lactalbumin) and Bos d 5 (beta-lactoglobulin)
- Does not measure: lactose intolerance, IgG, or non-IgE milk reactions
Known cross-reactions
- Goat's and sheep's milk
- Their proteins are very similar to cow's milk proteins. Most people sensitised to cow's milk also show antibodies to goat's and sheep's milk, both on the panel, so swapping is not a safe workaround without medical advice.
- Beef
- A small number of people sensitised to milk proteins, often to bovine serum albumin (Bos d 6, on the panel), also react to raw or lightly cooked beef. This association is uncommon.
Sources
- EAACI Molecular Allergology User's Guide 2.0. Pediatric Allergy and Immunology, 2023.
- World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines. World Allergy Organization Journal, 2010.
- Utility of casein-specific IgE levels in predicting reactivity to baked milk. Journal of Allergy and Clinical Immunology, 2013.
Page last updated
300 allergens. One test.
A finger-prick sample at home, sent by post. A detailed lab report typically 5 days after the lab receives your sample, and our plain-English guide to reading it. €300, €1 per allergen.
Questions
Will this test tell me if I am lactose intolerant?
No. Lactose intolerance is an enzyme issue, not an immune reaction, and IgE does not measure it. A doctor can advise on the right test for lactose intolerance.
Can I drink lactose-free milk if my result shows cow's milk?
Lactose-free milk still contains the full milk proteins, so it is not a fix for milk allergy. Discuss your result with a doctor before you change what you drink.
Why do I tolerate cheese but react to fresh milk?
Heat and processing change some milk proteins more than others. Whey proteins are more heat-sensitive than casein. An allergist can interpret what that means for you; do not experiment at home after a strong reaction.
Is this the same as an IgG food intolerance test?
No. We test IgE, the allergy-type antibody. The European Academy of Allergy and Clinical Immunology (EAACI) advises against IgG food tests for diagnosing food allergy or intolerance, and we do not offer them.