Spotting the symptoms of cows’ milk allergy

If your baby seems to have an adverse reaction after breastfeeding, bottlefeeding or eating foods containing dairy products, they may have cows’ milk allergy (CMA).

CMA affects a very small number of babies under the age of one. Unfortunately, it isn’t always easy to spot, with symptoms of milk allergy being similar to those of other medical conditions. Therefore, if you think your baby could have CMA, it’s important to talk to their doctor.

How to help your doctor make their diagnosis

Your baby’s doctor will want to know about any history of allergies in your family and the symptoms that have raised your concern.

The more evidence and information about the symptoms you can provide, the better. For example, if your baby comes out in a rash after feeding, take a photo of it and make a note of how long it takes to appear and how long it lasts. Likewise, note down details of any vomiting, diarrhoea, stomach cramps or difficulty breathing, and when these happen in relation to eating, drinking or other activities.

If two symptoms occur in two separate areas of the body, such as vomiting and a skin irritation, be sure to highlight this.

Why professional advice is best

CMA is difficult to diagnose, as other symptoms can mask the underlying cause. It is estimated that up to 15% of babies may show symptoms that suggest CMA but the actual incidence is only 2–7.5%¹.

Therefore, it’s important that you don’t self-prescribe or make any significant changes to your baby’s diet without the advice of a doctor. If your baby’s symptoms persist, you may need to see their doctor again.

Soya-based products in particular, including soya infant formula, are not recommended for babies under 6 months old. This is because they contain phytoestrogens (plant-based compounds with oestrogen-like properties), and research has shown that 30–50% of babies who react to cows’ milk-based formulas also react to soya-based formulas.

Another type of formula that isn’t suitable for babies with CMA is partially hydrolysed formula. These are widely available in supermarkets from well-known brands and often feature claims that they are easier to digest¹. However, their proteins are only partially broken down and can cause an allergic reaction.

A special milk for babies with CMA

If your baby is diagnosed with CMA, their doctor may prescribe a special kind of milk known as extensively hydrolysed formula. The protein in this type of formula has been broken down to a size so small that the baby’s immune system does not recognise it as an allergen. This process does not affect the nutritional value of the milk.

If your baby is displaying symptoms of CMA, you should speak to your health visitor or doctor as soon as possible.

Last reviewed: 28th July 2014