Cow’s Milk Allergy 101

Category: Newborns

Here’s what you need to know to figure out if your baby’s fussiness is typical baby behaviour or a sign of cow’s milk allergy.


Is your baby extremely fussy when it comes to his feeding time? Are you noticing any physical or behavioural changes every time you feed him his milk? If your answer to both questions is “Yes!”, you may want to consider the possibility that your baby has cow’s milk allergy.
Cow’s milk allergy is a type of food allergy typically occurring in babies and young children. It is a result of the immune system mistaking cow’s milk protein as harmful, which will then cause the body to release chemicals to fight off the protein. These chemicals are what cause the symptoms and allergic reactions to arise.

The good news is that cow’s milk allergy doesn’t usually persist into adulthood. Most children will grow out of the allergy by the time they reach the age of four.

Symptoms of Cow’s Milk Allergy
Learn to look out for the following symptoms if you suspect that your baby is allergic to cow’s milk. An immediate reaction may occur within minutes to two hours after your baby has consumed the milk. “Common symptoms include itching of the skin, flushing, hives or swelling of the eyes or lips. Tongue swelling, throat itchiness, voice hoarseness, vomiting and diarrhoea can also occur. In serious reactions, chest tightness, difficulty in breathing, very rapid heartbeat and low blood pressure may also occur,” says Dr Moira Chia, senior resident, Department of Neonatal and Developmental Medicine, SGH.   
Your baby may even display a delayed reaction after consumption of the milk. This may occur after one day or even one to two weeks later. These symptoms may include abdominal pain, bloody stool, vomiting, diarrhoea, colic and constipation. All of these symptoms may lead to poor weight gain in your baby. Eczema is also another delayed symptom to look out for.

Diagnosing Cow’s Milk Allergy
If you think that your baby may have cow’s milk allergy, consult a doctor immediately so that testing can be done.

Skin prick test
This involves the doctor placing a small amount of the cow’s milk protein on a small area of your baby’s skin. Thereafter, the skin will be gently pricked, and if a red weal appears after one to 20 minutes, this may indicate that your baby has a cow’s milk allergy.

Blood test
Your doctor may perform a blood test to confirm the results of the skin prick test. The blood test will involve your baby’s blood being analysed at the laboratory to check if it contains IgE (immunoglobulin E) antibodies. The immune system of babies who are allergic to cow’s milk will produce these IgE antibodies when cow’s milk is consumed, which will produce an allergic reaction. Hence, if the results of the blood test indicate a high level of IgE antibodies, this would mean that your baby has had an allergic reaction, thereby confirming the presence of cow’s milk allergy.

Elimination and challenge
Unfortunately, if your baby is experiencing delayed symptoms, it will be harder to diagnose if the symptoms are the result of cow’s milk since there are no reliable tests available. When this happens, it is recommended that you consult a dietitian, who will advise you on removing cow’s milk completely from your baby’s diet for a few weeks, and then gradually reintroducing foods that contain cow’s milk into your baby’s diet to monitor if the original symptoms resurface. This technique is known as elimination and challenge.
The first step to this technique is the elimination of milk-based foods. If your baby is being breastfed, your dietitian may advise you to avoid any foods that contain cow’s milk from your own diet as they can be passed to your baby through your breast milk.
For formula-fed babies, your dietitian may suggest that you switch to formula specially designed for babies with cow’s milk allergy. “Hypoallergenic formulas that use peptides or amino acids may be recommended. These formulas are produced by using enzymes to break down (hydrolyse) milk proteins, such as casein or whey,” says Claudia Correia, dietitian at Raffles Diabetes & Endocrine Centre. Since the milk proteins have been broken down, this means that they will not be recognised by your baby’s immune system, which will reduce the likelihood of any allergic reaction occurring in your baby.

If your baby’s symptoms improve after eliminating the milk-based foods, this may indicate the presence of cow’s milk allergy in your baby.

To ensure an accurate diagnosis, cow’s milk will need to be included back into your baby’s diet to see if the symptoms resurface. This is the second step to this technique, known as the food challenge. Your dietitian will advise you on slowly reintroducing milk-based foods into your baby’s diet and then monitoring for any signs of a reaction. The duration of the food challenge depends on how severe your baby’s original symptoms were. It can take up to a few hours (in this case, the food challenge may be done at the hospital) or if need be, your doctor may recommend you do the challenge at home and noting down your baby’s reactions.
If your baby’s symptoms – either immediate or delayed – reappear after the food challenge, then it is most likely that your baby has cow’s milk allergy. Of course, do remember that the elimination and challenge technique should be done only under the supervision of a dietitian or an allergy specialist.

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