Does my baby have cow's milk allergy or lactose intolerance?

You’ve probably heard of cow’s milk allergy, but lots of us are in the dark about what that actually means. Although it’s a common cause of food allergy in Australian babies – about one in every 50 bubs is affected – many people get it confused with lactose intolerance. While there are some similarities between the two conditions, they are managed in very different ways. We sought the help of Dr Preeya Alexander as a GP and health expert to explain the two conditions, and what to do if your newborn is affected. “Cows’ milk allergy (also known as cow’s milk protein allergy) and lactose intolerance are different conditions and I find patients are often confused between the two,” she says. “In cows’ milk allergy the child’s immune system will flare and react to the proteins in milk. The immune system is part of the issue in cows’ milk allergy. “Whereas in lactose intolerance the child’s gut has trouble digesting the sugar normally found in milk (both human breast milk and cows’ milk) – lactose. The immune system is not a factor.” Cow’s milk allergy can cause symptoms such as skin reactions and gastro-intestinal issues such as:

• Vomiting
• Diarrhoea
• Constipation
• Abdominal pain

Learn more on how to identify cow’s milk allergy here and get tips on how to manage it here. Here’s where the confusion lies: lactose intolerance can also cause vomiting, diarrhoea and abdominal pain. This overlap of symptoms is why you need a doctor’s diagnosis to determine which condition you’re dealing with. A key difference is that rashes and anaphylaxis (which can be life-threatening) can happen with cow's milk allergy but not with lactose intolerance, which is a much less serious condition. More information on the differences can be found here. If you think your child might be experiencing anaphylaxis (a severe allergic reaction), call 000 immediately.  

When should I reintroduce cow’s milk?

If your baby has been diagnosed with a mild-to-moderate cows’ milk allergy, your healthcare professional may use a guide called the ‘iMAP Milk Ladder’ to help you slowly reintroduce dairy into the diet after elimination. “The reintroduction of cow's protein into the diet (either in cow’s milk allergy or lactose intolerance) should always be done under medical guidance,” says Dr Preeya. “To put it very simply, the ladder starts with baked cow's milk protein, as it is usually less likely to cause issues. So, you may start with muffins or cookies, for instance, and slowly move up the milk ladder to eventually include foods like yoghurt and cheese. We monitor very closely for the development of symptoms such as irritability or gut symptoms as we do this.” When it comes to reintroducing foods containing lactose for a child with lactose intolerance, there’s a different timeline – but it still needs the supervision of a healthcare professional so that symptoms can be closely monitored. “Lactose intolerance is rare in babies – it tends to happen in older children,” Dr Preeya points out. “I always tell my patients not to self-diagnose and remove food groups without medical guidance, because it can lead to other issues such as nutritional deficiencies.”

Should I restrict other allergens?

One of the biggest misconceptions parents have about cow’s milk allergy or intolerance, says Dr Preeya, is the idea you should eliminate other foods that could cause allergic reactions, such as peanuts and egg. This isn’t true, she says. In fact, if you avoid other allergens you could accidentally contribute to other problems down the track. “I understand why parents will become reluctant to introduce other allergy foods – they have usually lived with a distressed and irritable infant when the cow’s milk allergy was diagnosed, and they are reluctant to live it all again,” she says. “However, introducing allergy foods, like peanut protein, soy and egg, before the age of one can reduce the risk of food allergies developing.”

The good news

If you’re finding it tough to deal with a cow’s milk allergy or lactose intolerance, go easy on yourself. Dr Preeya says it’s an exhausting situation, but there is always light at the end of the tunnel. “Parenthood is exhausting enough when everything is going okay, but if you add dietary restrictions and an irritable infant it can be really tricky,” she says. “I’ve seen patients in tears so many times over things like this and it’s so wonderful seeing them come out the other end when we identify what is going on and the infant is more settled.” REMEMBER: This article is not to be substituted for medical advice. If you’re concerned about your baby’s diet, or have questions about cow's milk allergy, lactose intolerance or any other conditions, please speak to a healthcare professional such as a pharmacist, GP or maternal child health nurse. Disclaimer: Dr Preeya Alexander is an independent expert who was compensated for her time.