Recognising the signs of
milk allergy and intolerance in babies

Milk allergy and intolerance in babies

Babies can either be allergic or intolerant to milk. An allergy is more serious than an intolerance but some of the symptoms are similar, making them difficult to diagnose.

A milk allergy involves an immune reaction to one or more of the proteins present in milk, whereas an intolerance does not involve the immune system. An intolerance is caused by an inability to deal with certain substances in milk, such as lactose. One example which is often talked about is lactose intolerance, where some individuals don't produce any or enough of the enzyme lactase which breaks down lactose. Undigested lactose causes uncomfortable symptoms like diarrhoea, bloating and wind.

Recognising a milk allergy

If your baby is allergic to milk, they will react to cows’ milk, formula based on cows’ milk and sometimes, but very rarely, your breastmilk if you’ve recently eaten or drunk dairy products. Things to look out for include stomach cramps, vomiting, diarrhoea, rashes, hives, eczema, and difficulty breathing. Individual symptoms can sometimes be related to a bug, but if your baby is affected in two separate areas of the body – for example the stomach and skin in the form of vomiting and hives – you should ask your health visitor or doctor for advice.

It’s common for babies who are allergic to cows’ milk to be allergic to goats’ milk and other animal milk too, as they contain similar proteins. Unfortunately there is no single diagnostic test for cows' milk protein allergy and a combination of tests and a series of elimination and reintroduction diets are often necessary. These tests usually happen once your baby has been referred to a specialist by your doctor. It's important that you seek advice from your doctor if you suspect that your baby has an allergy so that they can be properly diagnosed and treated.

Feeding and milk allergies

Managing a cows' milk protein allergy involves removing all cow's milk from your baby's diet, so you'll need to get familiar with reading food labels and ingredients as milk can occur in unlikely places. Food labelling laws are there to help you and common allergens, like milk, have to be declared on pre-packaged foods.

If your baby is being formula fed, and has been diagnosed with cows’ milk protein allergy, your doctor may prescribe an extensively hydrolysed formula. The protein in these formulas has been broken down into smaller pieces so that the baby’s immune system does not recognise it as an allergen – a process which does not affect the nutritional value of the formula. We’ve created Aptamil Pepti 1 and 2 using extensively hydrolysed whey to create special formulas that are suitable for babies with a cows’ milk protein allergy. It’s easier to digest and it provides the nutritional care your baby needs without upsetting their allergies. Soya formulas are not recommended before 6 months as they contain phytoestrogens and infants who react to cows’ milk-based formulas often also react to soya-based formulas.

In rare cases your baby may be reacting to the milk proteins passing from your diet into your breastmilk. If your baby is diagnosed with cows' milk protein allergy and you’re breastfeeding, you may have to change your diet - but this should only ever be done after consulting with your healthcare professional.

Are milk allergies common?

Only around 2–7.5% of babies under 1 year old are allergic to cows’ milk. By the age of three most children will have grown out of cows’ milk allergies, but for a few it may last until they're 6-8 years old. Occasionally, it can continue into adulthood – especially if there is a family history of allergies.

How to identify a lactose intolerance

A lactose intolerance usually causes less severe reactions than an allergy. As with a milk allergy, symptoms of a lactose intolerance can include diarrhoea, vomiting, and stomach cramps but not usually hives or breathing difficulties. Another difference is that a lactose intolerance won’t show up in a blood or skin-prick test. Still, your baby’s reaction will be noticeable, if not as severe as that of an allergy.

There are two main types of lactose intolerance. The first is primary lactose intolerance, and is caused by a deficiency in the enzyme lactase. It normally affects Hispanic, Asian and American Indian populations, but is uncommon in Europeans – also, the condition doesn’t often show signs in the first year of life. But it doesn’t mean that lactose has to be removed from the diet entirely: depending on the individual, those with primary lactose intolerance can often tolerate a certain amount of lactose. Secondary lactose intolerance is usually caused by damage to the gut, after a severe stomach bug for example. But this form of the condition is usually temporary until the gut heals. In very severe cases, lactose may need to be removed from the diet for a few weeks, but should only be done so on the advice of a healthcare professional.

Before you worry too much about allergies and intolerances, it’s worth remembering that babies and small children often pick up common bugs, when they come in to contact with other children, which can have similar unpleasant effects. But if your baby’s symptoms persist or you notice a pattern occurring, you should seek advice from your doctor.

If you suspect your baby has either a milk allergy or intolerance, speak to your health visitor or doctor. If you have any other questions about feeding or allergies, contact our experts anytime on 0800 996 1000, or get in touch via Live Chat, our online messaging service, between 8am-8pm, Monday to Friday.