Milk allergy

Cow's milk is a common cause of food allergy in infants. Although most children out grow cow's milk allergy by the age of 4 years, persistent cow's milk allergy may sometimes occur. However, ongoing symptoms in adults are very rare.

  

If your child has milk allergy, these symptoms may occur:

1. within minutes or up to one hour after having a small amount of cow's milk.
   Symptoms may include hives (urticaria), eczema, face swelling, vomiting, diarrhoea, noisy breathing or wheeze. Severe allergic reactions (anaphylaxis) may cause floppiness in babies.
2. several hours after having moderate amounts of cow's milk.
   Symptoms can include vomiting and diarrhoea and sometimes blotchy rashes or worsening eczema.
3. after a day or up to several days after having normal amounts of cow's milk.
   Symptoms can include eczema, vomiting, diarrhoea or asthma.
   

 

Reliable diagnosis is important

 

In people with immediate (within minutes or up to 1 hour) allergic reactions to milk, diagnosis is usually obvious. This can be confirmed by your doctor using allergy tests (skin prick tests or blood allergen specific IgE [RAST] tests).

Treatment involves avoidance of dairy products

 

Treatment of cow's milk allergy involves elimination of cow's milk and its products from the diet and substitution with an appropriate formula in babies. However, avoiding dairy products in children is not easy. Most children allergic to cow's milk will be allergic to goat's milk, so products made from goat's milk are not only inadequate substitutes, but usually trigger similar symptoms. It is therefore important to read all labels of prepared foods and avoid any food which contains cow's or goat's milk, cheese, butter, butter milk cream, cream fraiche, milk powder, whey, casein and margarines which contain milk products.

Dietary restrictions should be supervised

 

It is important to note that elimination and reintroduction of cow's milk and dairy products should only be undertaken with advice from a medical specialist, particularly in cases with severe symptoms. Elimination of cow's milk entirely from the diet is usually difficult and needs to be done in consultation with a specialist dietitian. If long term exclusion is required, patients require an alternative source of calcium and protein, and advice from a dietitian should be sought. This applies to the affected child, and to their mother if dietary exclusion during breast feeding is required.  After confirming cow's milk allergy, your doctor will usually recommend replacing dairy products with alternative formulae, which may include:

1. Soy protein formula
   Around 50 to 80 per cent of children with cow's milk allergy can tolerate soy based formulae. However, in children allergic to soy as well, it is not a suitable substitute.
2. Extensively hydrolyzed formula (EHF)
   This is cow's milk based formula that has been treated with enzymes to break down most of the proteins that cause symptoms in infants who are allergic to cow's milk. These are usually supplements of first choice in milk allergic children. However, since some children will still react to this formula, sometimes an amino acid based formula is advised. Extensively hydrolyzed formula is different to partially hydrolyzed formula and the latter is not suitable for treatment of milk allergic children.
3. Amino acid based formula
   This formula is necessary in around 10 per cent of children with cow's milk allergy. This formula will be tolerated by almost all children with soy or cow's milk allergies.
   
   
   

Some formulas are unsuitable for children with cow's milk allergy

 

Children allergic to cow's milk are usually allergic to a number of proteins present in dairy products. Since similar proteins are present in other animal milks such as goat milk, these products can also trigger allergic reactions, and should be avoided.

There may be other food allergies, as well as milk

 

Cow's milk allergy may occur together with other food allergies such as egg, soy, peanut or other nuts. This is referred to as multiple food allergy. Confirmation of this usually requires a referral to a medical specialist (Allergist / Clinical Immunologist).

Cow's milk allergy usually resolves

 

Around 80 per cent of babies will grow out of their allergy by the age of 4 years. Assessment of this likelihood and reintroduction of dairy products should be done in association with a medical specialist. Depending on the history and severity of the original reactions, this may require further allergy testing and deliberate food challenge, which is usually performed in a hospital setting.

Not all reactions to milk are due to allergy

 

Lactose intolerance is caused by the lack of the enzyme lactase, which helps to digest the milk sugar lactose. The symptoms are diarrhoea, vomiting, stomach pain and gas, which are similar to some of the symptoms of milk allergy. This condition is uncomfortable but not dangerous, and does not cause rashes or anaphylaxis. Small amounts of cow's milk are usually tolerated, and yogurts and hard cheeses are usually tolerated better than milk, as they contain less or easier to digest lactose than cow's milk. Treatment may involve reducing or avoiding consumption of dairy products containing lactose and substituting these with a lactose free formula or milk.