Cow's Milk Protein Intolerance


Newborn babies and infants in the first six to twelve months of life are very often temporarily allergic to cow’s milk. This condition is also called dairy allergy, cow’s milk protein intolerance or cow’s milk protein enteropathy.

The purpose of this leaflet is to help parents understand about dairy allergy and to describe our approach to treatment if required. It is not meant as an alternative to seeking medical attention and will always be used in combination with a medical assessment to ensure that allergy is the cause of a baby’s symptoms.


What is dairy allergy?

Foods contain a combination of carbohydrate (sugar), protein and fat together with vitamins and minerals. The protein in different milks varies depending on where the milk comes from – e.g. human breast milk contains human milk protein, cow’s milk contains cow’s milk protein (dairy protein) and soy milk contains soy milk protein.

Some babies and infants are allergic to the protein in cow’s milk. This condition is nothing to do with allergy to lactose (or lactose intolerance); lactose is the sugar (or carbohydrate) in milk. Lactose intolerance is quite rare and causes different symptoms.

Exclusively breast fed babies receive only human milk protein. However, a mother’s diet may alter the protein in her breastmilk. Cow’s milk protein taken by a mother in her diet is digested (broken down) and absorbed in her gut. It is then used by her breasts to make human milk protein. If the human milk protein in her breast milk contains enough of the building blocks of cow’s milk protein, it can cause dairy allergy in the baby.

Most formula fed babies, and breastfed babies who receive supplementary bottles of formula, are exposed to cow’s milk protein. Most infant formula is made using powdered cow’s milk that has been substantially adapted. These formulas may cause dairy allergy in a baby or infant. Some other formulas are available that are based on different proteins – e.g. soy milk formula, rice milk formula. These may be used as an alternative to cow’s milk protein formula (see later).

Babies usually start taking solids at around six months of age. After starting with pureed fruit and vegetables, milk protein is introduced in the form of yogurt. By 7-8 months of age, most babies are also taking cheese, and by 12 months, straight cow’s milk in their cereal. A baby with dairy allergy may start to show symptoms when solids are introduced.


Why has my baby developed dairy allergy?

Cow’s milk protein allergy is very common. In most cases, the cause is unclear. Sometimes there is a history of another family member being affected – e.g. a parent, sibling or more distant relative. If this is the case, there may be a genetic tendency to dairy allergy; the genes that cause dairy allergy are not well understood at the moment.


What problems does dairy allergy cause?

The signs of dairy allergy may vary greatly from one baby or infant to another. Most people think of allergy as an immediate and severe reaction to something – e.g. rash, lip swelling and difficulty breathing after a bee sting or eating eggs or nuts. This type of immediate allergy is called anaphylaxis – it is rare in dairy allergy.

Most babies and infants with dairy allergy have one or more of the following symptoms:


  • Skin rash – this may be simply some redness around the mouth and face during or shortly after feeding. Some babies may develop more extensive eczema with dry skin on the face, trunk and limbs especially affecting the skin creases. When eczema develops in the first six months of life, it is almost always related to allergy (eggs and/or nuts may cause allergy as well as dairy)
  • Difficulty with feeding – babies with dairy allergy are often difficult to feed. They may start and stop often, become irritable and not complete feeds. As a result, they may feed very frequently.
  • Vomiting and/or regurgitation – in the past, many babies with vomiting and irritability during and after feeds were labelled as having ‘reflux’. Actually, true gastro-oesophageal reflux is rare and most babies with these symptoms actually have dairy allergy.
  • Abdominal pain and/or irritability – this is the commonest symptom of dairy allergy. The cow’s milk protein causes inflammation in the lining of the bowel. This causes excessive crying in the baby. Most babies cry for a few hours each day (usually towards the end of the day and not during feeds) but babies with dairy allergy are often very unsettled at all times of day and particularly during feeding.
  • Alterations to the stool (poo) – breast fed babies usually start off passing sloppy yellow poos (like Dijon mustard) with each nappy change. With time, they stool less often and by six weeks, are passing three to four poos each day. Formula fed babies usually pass thicker green poos (like toothpaste) one to two times per day. Babies with dairy allergy often pass very frequent, green poos which are more liquid, sometimes explosive, and which may contain mucus and small amounts of blood. In addition, babies with dairy allergy often pass large amounts of offensive gas.


These signs of dairy allergy may be present from birth, or develop in the first few months of life. While a few infants may continue to have dairy allergy into later childhood, and rarely into adulthood, in most infants the allergy disappears in the second six months of life. Thus, for most infants, dairy containing solids can be introduced at the usual times without any symptoms. When dairy allergy persists into adulthood, most of those affected say that they have lactose intolerance – in fact, most of them are actually dairy intolerant.


How is dairy allergy treated?

The main treatment for dairy allergy is to avoid exposing the baby or infant to cow’s milk protein. For formula fed babies, or breastfed babies receiving supplementary formula feeds, this means a change of formula:


  • Rice milk protein formula - to start with, we recommend switching to a rice milk protein formula such as Novalac Allergy. This is available in supermarkets and across the counter in pharmacies.
  • Extensively hydrolysed cow’s milk protein based formula – if switching to rice milk protein formula does not improve the symptoms, we recommend using a cow’s milk protein formula in which the chains of protein have been substantially broken down (or hydrolysed) – e.g. Alfare, Aptamil Gold Pepti Junior. These formulas are expensive and require an authority prescription which we will provide after contacting the government to obtain approval. They are not standard stock for a pharmacy but can usually be ordered in within 24 hours.
  • Elemental formula – if switching to extensively hydrolysed formula does not improve the symptoms, the final step is to use an elemental formula – e.g. Alfamino, EleCare, Neocate. These are cow’s milk protein formulas in which the chains of protein have been completely broken down into individual amino acids (the building blocks of protein). They also require an authority prescription which we will provide and are not standard pharmacy items.


If a baby or infant is breastfeeding and receiving supplementary formula feeds, then apart from changing the formula as described above, the breast feeding mother will need to go on a strict dairy exclusion diet (see below).


Exclusion diet for breastfeeding mothers

Breastfeeding mothers need to avoid foods containing dairy protein. These include: butter; cheese including cheese spreads, cottage cheese, cream cheese, feta cheese and ricotta cheese; condensed milk; cream; custard; evaporated milk; ghee; ice cream; milks including lactose free/low fat/skimmed/A2/UHT (almond, coconut, oat and rice milks are ok); probiotic drinks; Sustagen and high protein drink powders; sour cream; cow’s milk yoghurt.

It is also important to exclude foods containing milk solids. This list is less intuitive to most people. It includes: biscuits; breads; breakfast cereals; cakes; canned spaghetti; caramel; fudge; butterscotch; chocolate; many confectionary types; creamed soups; crumbed and battered products; dips; drinking chocolate, Milo and malted milk powder; gravy powders; margarine; milk ice confectionary; creamy pasta sauces; some potato products including mash, salads and instant potato; processed meats including sausages, sandwich meats and hamburgers; most sorbet and gelato; salad dressings; snack foods including crisps, crackers and some pastry items.

To most people, avoiding milky things in their diet is obvious but the key to the diet is careful label reading avoiding items foods containing milk solids. The diet should be continued until the baby can tolerate dairy containing solids in his/her diet; this is a sign that the allergy is resolving.