How common is cow’s milk allergy?

Cow’s milk allergy is common in infants and young children. It is estimated to affect 2-3% of children under one year old.

What are the symptoms of cow’s milk allergy?

Immediate reactions. Fifty percent of infants have symptoms that begin straight away. These include hives / “nettle” rash and swelling of the lips. Some children feel sick, vomit or have diarrhoea. Severe reactions (anaphylaxis) are much less common, but include difficulty breathing (wheeze or throat swelling), feeling faint or dizzy.

 Delayed reactions These occur hours or up to a day or two after eating the food. They include flares of eczema, vomiting after feeds, colic and diarrhoea (sometimes with blood in the stools).

What about lactose intolerance?

This is not an allergy but an inability of the gut to breakdown milk sugar (lactose). It causes watery diarrhoea, flatulence and / or stomach cramps. This usually follows a bout of gastroenteritis and gets better a few weeks after the tummy upset resolves.

How serious is cow’s milk allergy?

Most children have mild reactions. Severe reactions are uncommon but need urgent medical attention.


Are children likely to be allergic to other foods?

Children with cow’s milk allergy are usually allergic to goat’s and sheep’s milk. A smaller number of children will also have a soya milk allergy.  It is uncommon for a baby with a cow’s milk allergy to react to breast milk. Mother should not exclude cow’s milk and dairy from their diet without prior professional advice.

Alternative low allergy milk formulas include SMA Althéra, Aptamil Pepti 1 or 2 and Nutramigen LLG. A few babies will also have symptoms on these formulas and need more specialised amino acid formulas. Soya protein-based formulas can be considered in infants over 6 months old.

How do we diagnose cow’s milk allergy?

The diagnosis is usually based on a history of a typical reaction. If the reaction is immediate skin prick tests or specific IgE blood tests can be helpful. Allergy tests are not helpful in the diagnosis of delayed allergic reactions, such as in flares of eczema.

What dairy products should my child avoid?

80% of children who react to fresh milk tolerate baked milk in biscuits and cakes. In this case, your child should continue to eat the baked milk products to maintain and improve their tolerance.

Children who are allergic to cow’s milk should avoid full fat, semi-skimmed, skimmed, sterilised, evaporated and condensed cow’s milk. Other products to avoid include:

milk powdermilk solidsnon-fat milk solidsbutter / buttermilk
cheesecreamice creamyogurt
fromage fraiscrème fraichecaseincaseinates
gheewheywhey hydrolysatemargarine

Cooking and heating make milk proteins less allergic. 80% of children reacting to fresh milk will tolerate baked milk in biscuits and cakes. If so, the child should continue to consume these baked milk foods.

Because of potential nutritional deficiencies, particularly in young infants, advice from a paediatric dietitian is recommended. Your dietitian can advise on alternative milk formulas, and sources of vitamins and calcium for you and your baby.

What can I do if my child has a reaction?

A written management plan will be given in clinic. Allergy medication should be available at all times.

 If a child gets hives or swelling, tell them to spit the food out, and then give them an antihistamine.

 Severe symptoms:

  • Difficulty breathing (wheezing, noisy breathing, blue colour)
  • Swelling in the throat (noisy breathing, drooling) and tongue
  • Feeling faint or dizzy, looking very pale (lie the child down with their legs raised).

If any of these severe symptoms occur get help straight away and dial 999 stating “anaphylaxis” (ana-fil-ak-sis).

Delayed reactions may be troublesome, but rarely cause life-threatening symptoms and the mainstay of treatment is avoidance.

Who needs to know about this allergy?

Inform the nursery/school and after-school clubs. Grandparents, relatives and school friends’ parents will also need to know. We suggest sharing the child’s allergy plan with them.

How do I know when my child has outgrown their cow’s milk allergy?

Four out of five children will outgrow their milk allergy by school age.  Children should be reviewed every 6 months to see if they still need to avoid dairy. Your allergy team can provide advice on how to increase the amount of baked or processed milk products (milk ladder). This will help your child outgrow their milk allergy more quickly. Click on the icon to review our guidelines for home milk challenge.