Cow's Milk Allergy
Also known as: CMA, Dairy allergy, Milk protein allergy
Cow's milk allergy (CMA) is one of the most common childhood food allergies, affecting 2–3% of infants. It involves an immune response to milk proteins — casein and whey — and is distinct from lactose intolerance, which is not immune-mediated.
Category
Food Allergies
Severity
Moderate to SeverePrevalence
2–3% of infants and young children; most outgrow it by school age.
Symptoms
Airways & Breathing
- Runny nose
- Wheezing
- Cough
Skin
- Eczema
- Hives
- Perioral redness
Digestive
- Vomiting after feeds
- Diarrhoea
- Blood in stool (non-IgE mediated)
- Reflux-like symptoms
- Colic
Systemic / Other
- Anaphylaxis (IgE-mediated)
- Failure to thrive in severe cases
How It's Diagnosed
- Skin prick test and specific IgE to milk, casein, alpha-lactalbumin, and beta-lactoglobulin
- Exclusion diet followed by structured re-introduction (oral food challenge) under supervision
- Patch testing for delayed/non-IgE presentations
Avoidance Strategies
- Avoid all cow's milk products: milk, cheese, butter, cream, yoghurt, ghee, casein, whey
- Check labels for 'contains milk' and hidden dairy in bread, biscuits, processed meats, soups
- Suitable alternatives include oat milk, soy milk (if tolerated), rice milk, or hydrolysed formula for infants
- Goat's milk proteins cross-react with cow's milk — it is NOT a safe substitute
Cross-Reactivity
- Goat milk and sheep milk — significant cross-reactivity, avoid if cow's milk allergic
- Beef — about 10–20% of cow's milk allergic children also react to beef
CMA vs lactose intolerance
These are completely different conditions. Cow's milk allergy is an immune-system reaction to milk proteins. Lactose intolerance is the inability to digest lactose (milk sugar) due to low enzyme levels — it causes gut symptoms but no immune reaction and is never life-threatening.
If you are lactose intolerant, lactase enzyme supplements or lactose-free dairy products are usually well tolerated. If you have CMA, you must avoid the proteins themselves.
Will my child outgrow it?
Most children with CMA outgrow it. Roughly 50% tolerate milk by age 1, 75% by age 3, and 90% by school age. The chance of resolution is higher for non-IgE mediated (gut/skin) forms than for IgE-mediated (immediate, anaphylactic) forms.
Regular supervised re-testing with an allergist is important — do not attempt home challenges.
Related Allergens
Medical disclaimer
This page is for educational purposes only. Allergy diagnosis and management must be carried out by a qualified allergist. Do not attempt to test yourself with suspected allergens. Always carry prescribed emergency medications and follow your written action plan.
Reviewed 2026-06-01 · Looms Medical Team