Milk Allergy – The Facts
Cow’s milk allergy happens when the body’s immune system wrongly identifies proteins in cow’s milk to be a threat.
In the UK, cow’s milk allergy affects 2-3 out of 100 babies. Cow’s milk allergy usually starts in babies under 12 months of age, with most outgrowing their allergy during childhood. Cow’s milk allergy is uncommon in adults.
Older children and adults who are allergic to cow’s milk tend to have a more serious cow’s milk allergy.
What are the types of cow’s milk allergies?
There are two types of cow’s milk allergy, immediate and delayed. With both types of cow’s milk allergy, there is often (but not always) a close family history of allergies such as eczema, hay fever, asthma or food allergy in a mother, father, brother or sister.
Immediate cow’s milk allergy
Immediate cow’s milk allergy is also called ‘IgE mediated’ as it involves IgE antibodies, which are part of the immune system. Reactions are usually very fast and happen between minutes and up to 2 hours after drinking cow’s milk or eating dairy-containing foods.
Symptoms can vary, but in some people, this type of allergy has the potential to cause a severe, life-threatening allergic reaction called anaphylaxis.
The symptoms of an immediate cow’s milk allergy are:
Rash (known as hives or urticaria)
Swelling of the skin (known as angioedema) anywhere on the body (e.g. lips, face)
Stomach pain, feeling sick and vomiting
Change in behaviour
Delayed cow’s milk allergy
Delayed cow’s milk allergy is also called ‘non-IgE mediated’ as it involves a different part of the immune system, not involving IgE antibodies. Symptoms can vary, but mainly affect the digestive system and the skin.
Symptoms usually occur between 4 - 48 hours after drinking cow’s milk or eating dairy containing foods.
The symptoms of delayed cow’s milk allergy are:
Diarrhoea (which might be bloody)
What are the severe symptoms of a milk allergy?
The term for a more serious reaction is anaphylaxis.
In extreme cases, there could be a dramatic fall in blood pressure. The person may become weak and floppy and may have a sense of something terrible is happening. This may lead to collapse and unconsciousness and on rare occasions can be fatal.
Most health care professionals consider an allergic reaction to be anaphylaxis when it involves the ABC symptoms:
Airway - swelling in the throat, tongue or upper airways (tightening of the throat, hoarse voice, difficulty swallowing)
Breathing - sudden onset wheezing, breathing difficulty, noisy breathing
Circulation - dizziness, feeling faint, sudden sleepiness, tiredness, confusion, pale clammy skin, loss of consciousness.
Milk Allergy FAQs
If you suspect you or your child is allergic to cow’s milk, you must see your GP.
If you need to be referred to a specialist allergy clinic, your GP can locate one in your area by visiting the website of the British Society for Allergy and Clinical Immunology (BSACI).
For those with immediate cow’s milk allergy, mild allergic symptoms can be treated with antihistamines.
If there is a risk of anaphylaxis, adrenaline auto-injectors (AAIs) will be prescribed. Two AAIs should be available at all times and it is important to know how and when to use them. An AAI should be used as soon as anaphylaxis is suspected, and a second AAI can be used after 5 minutes if symptoms don’t improve or get worse.
After the first AAI is used, someone must dial 999 immediately. The emergency service operator must be told the person is suffering from anaphylaxis (pronounced ana-fill-axis).
If you are allergic to cow’s milk you need to read food labels carefully. When eating out in restaurants, takeaways and other catering establishments question staff directly about ingredients.
Cow’s milk may also be found in some cosmetics and personal care products – it is important to read labels carefully.
Cow’s milk protein can be found in the following foods and ingredients:
Butter, buttermilk, butter oil, ghee and margarine
Casein (curds), caseinates, hydrolysed casein, calcium caseinate, sodium caseinate
Cheese, cheese powder and cottage cheese
Cow’s milk (fresh, condensed, dried, evaporated, powdered e.g. infant formulas)
Cream, sour cream, crème fraiche and ice cream
Lactalbumin and lactoglobulin
Whey, hydrolysed whey, whey powder, whey syrup sweetener
Yogurt and fromage frais
Cow’s milk is a source of protein, energy, fat, vitamins and minerals (such as calcium and iodine). If you or your child have a cow’s milk allergy, your GP or allergy clinic can refer you to a dietitian.
This is important as a dietitian can give advice about which foods to avoid and suggest dairy-free alternatives, so you can achieve a balanced diet. Your dietitian can also advise whether it is necessary to take a vitamin or mineral supplement.