Lactose intolerance symptoms in babies

Lactose intolerance symptoms in babies

Lactose intolerance is a digestive problem where the body doesn’t produce enough natural enzymes to digest foods with lactose, namely milk and dairy products. Read more about lactose intolerance in babies, how to spot the symptoms, and how to ensure your baby still gets a balanced diet.


Symptoms of cows’ milk protein allergy (CMPA) usually appear during the first few months of life. CMPA is more likely to occur between a week to a month after formula or cows’ milk is introduced and is rare in exclusively breastfed babies. In these rare instances, the milk proteins from your diet may pass through your breastmilk to your baby. However, you should only remove dairy products from your diet on the advice of a healthcare professional as they are an important source of key nutrients, like calcium.

If your baby is allergic to cows’ milk then it is likely that they will also react to goat, sheep, buffalo and other animal milks. If you don’t think your baby is feeding as they should, it’s always best to seek advice from your doctor. However, this article will help you to understand more about milk allergies and learn how to identify possible reactions to milk.

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.

How to identify 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. The symptoms of a milk allergy can include stomach cramps, vomiting, diarrhoea, rashes, hives, eczema, and difficulty breathing.

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. 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.

If your baby is diagnosed with cows’ milk protein allergy and you’re breastfeeding, in rare cases your baby may be reacting to the milk proteins passing from your diet into your breastmilk. If this is the case 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 lactose intolerance in babies?

A lactose intolerance is less threatening than an allergy. As with a milk allergy, symptoms of a lactose intolerance in babies 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.

The most common type of lactose intolerance in babies is called ‘secondary lactose intolerance’. This occurs because another condition, such as gastroenteritis or the inflammation caused by cows’ milk protein allergy, reduces the production of lactose by injuring the gut. This is only temporary until the gut recovers. Lactose may need to be taken out of the diet in severe cases but not permanently. If this is the case then you should always seek advice from your healthcare professional.

If you suspect your baby has either a milk allergy or intolerance, speak to your doctor. Or if you have any other questions about feeding or allergies, our Careline team is available on 009647723342222 between the hours of 9am and 5pm Saturday to Thursday.

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