Allergies and intolerances in babies


If you’re a parent of a baby with colic, you might have wondered if the symptoms you’re seeing could be due to an undiagnosed condition in your baby.

Sometimes,  the symptoms that are commonly related to colic could be signs of an allergy or intolerance.

Some of the most commonly queried food allergies or intolerances of parents of babies include Cow’s Milk Protein Allergy (CMPA), Cow’s Milk Protein Intolerance (CMPI), soy allergy or intolerance, or lactose intolerance. Often these conditions run in families.

This article discusses the common symptoms and differences between each of the conditions.

Cow’s Milk Protein Allergy (CMPA)

One of the most common allergies or intolerances in babies and children is cow’s milk protein allergy. Cow’s milk protein allergy occurs when the body reacts to the proteins in cow’s milk. For a bottle fed baby, these proteins are present in their formula. For a breastfed baby, the protein are passed through the mother’s breast milk to the baby.

Common symptoms of CMPA can include:

– frequent regurgitation or reflux
– diarrhea or constipation
– blood in stools
– chronic coughing or wheezing
– persistent nasal congestion
– skin conditions such as dermatitis or eczema
– frequent unsettled behaviour or constant unexplained crying

It is important for parents to understand that this is a rare condition that occurs in approximately 1% of the population* and that these symptoms may appear in a baby without the presence of an allergy. CMPA is strongly associated with familial atopic eczema.

For breastfed babies who have been medically diagnosed with CMPA, breastfeeding mothers will need to follow a strict dairy elimination diet, to ensure that cow’s milk proteins are not passed to their baby through their breast milk. For a bottle fed baby, a specially hydrolysed formula will be prescribed by your doctor or pediatrician.

It’s important to note that unless your baby has been medically diagnosed with CMPA, it is not advised to start a breastfeeding elimination diet or special infant formula, unless advised by a health care professional. CMPA must be diagnosed with allergy and blood test.

Cow’s Milk Protein Intolerance (CMPI)

Cow’s milk protein intolerance is different to an allergy as it does not create an immune response in the body. It can however cause gastrointestinal symptoms and some parents find that eliminating cow’s milk from their baby’s diet relieves these symptoms. The proteins in goat milk formulas often elicit the same symptoms in babies as cow’s milk proteins, and therefore not suitable for babies with CMPA or CMPI. For breastfed babies, breastfeeding mothers might find that following a strict dairy elimination diet helps to ease gastrointestinal troubles in their baby.

Intolerances should be diagnosed by a health professional.

Soy allergy / intolerance

It’s common for babies with a CMPA or CMPI to also be allergic or intolerant to soy. Around sixty percent of babies who are intolerant to cow’s milk protein will also develop an intolerance to soy.

Symptoms of a soy allergy are similar to CMPA or CMPI and can include the following:

– coughing or wheezing
– bloating or tummy pains
– diarrhea

Once again, it’s important for parents to have a formal diagnosis of a soy allergy or intolerance rather than making assumptions regarding their baby’s symptoms, leading to treatment of a condition that has not been formally diagnosed.

Many parents are surprised to discover how many food products contain soy. For breastfeeding mothers, total elimination of soy from the diet is often the only way to relieve symptoms of soy intolerance in their baby. For bottle fed babies, it is important to discuss a suitable alternative to cow’s milk or soy based formula with your healthcare provider.

Lactose intolerance

Lactose intolerance is different to CMPA or CMPI and is related to the sugars (lactose) that are present in breast milk, infant formula, and cow’s milk. Lactose intolerance occurs when your baby has troubles digesting the sugars in milk. This is different to lactose overload, which is a condition sometimes present in breastfed babies of mothers with an oversupply of
breast milk.  A lactase deficiency (low or absent level of the lactase enzyme in the in the small intestine) precedes lactose intolerance.  Congenital lactose intolerance in babies is very rare.

Symptoms of lactose intolerance can include:

– wind
– bloating
– diarrhea
– tummy pain
– faltering growth

These symptoms can sometimes be present in babies for reasons other than lactase deficiency or lactose intolerance. If you have a family history of lactose intolerance, and you
suspect this could be the case for your baby, It’s important to speak to your GP for a medical diagnosis and advice.

For more information, refer to ASICA:  Australasian Society of Clinical Immunology and Allergy: https://www.allergy.org.au/

*JAMA pediatri. 2020;174(6):599-608