What is a baby runny nose?

Runny nose can be identified as streaming mucous from a baby’s nostrils. A baby’s immune system is immature, which makes them more vulnerable to illness. For some babies, it may seem like they have a constant runny nose, however this may likely be the result of a baby having back-to-back cold virus infections.

What causes a baby to have a runny nose and sneezing?

Sneezing is a natural reflex mechanism used to clear airborne substances and congestion from the respiratory and nasal passages. It is very common in babies and not usually something to cause concern.

Possible causes of a baby runny nose may include:

  • A food allergy, e.g. Cows’ Milk Allergy (CMA)
  • Having an illness of the upper airways such as a cold virus
  • Inhaling dry air or irritants, such as cigarette smoke and dust

Could it be Cows' Milk Allergy?

Baby runny nose and sneezing are common symptoms for babies with CMA. Babies with CMA usually experience more than just one symptom and these symptoms can be very different from one another.

If you think that your baby has a runny nose or is sneezing, it may be CMA. You may have even noticed other symptoms (besides runny nose and sneezing), which may affect other parts of your baby’s body.

A baby with CMA can experience a runny nose as soon as 30 minutes after having cows' milk

For a simple and easy way to understand the symptoms associated with CMA, you can use our symptom checklist or symptom diary to track symptoms

This will allow you to select all the symptoms that your baby may have that may be cows’ milk-related. You can then discuss these with your doctor.

In any case, if you have any doubts or concerns about your baby’s health, you should always seek advice from a medical professional as soon as possible. The information on this website should not replace medical advice from a medical professional.

SmilesBack App

Cows’ milk allergy (CMA) is a common food allergy in baby’s and young children but it is often challenging to diagnose and may take many months and doctors appointments. If you suspect that your baby might have cows’ milk allergy, you can use SmilesBack to help shorten the journey to diagnosis and help put smiles back where they belong.

SmilesBack is an easy-to-use app that has been developed with allergy experts and tested by parents. It enables you to easily record your baby’s symptoms and feeds and summarise them in a one-page, expert-designed report, to support your doctor before they make a diagnosis.



IMPORTANT NOTICE: Breastfeeding is the best form of nutrition for babies and provides many benefits to babies and mothers. It is important that, in preparation for and during breastfeeding, you eat a healthy, balanced diet. Combined breast and bottle feeding in the first weeks of life may reduce the supply of your own breastmilk, and reversing the decision not to breastfeed is difficult. Always consult your healthcare professional for advice about feeding your baby. The social and financial implications of using infant formula should be considered. Improper use of an infant formula or inappropriate foods or feeding methods may present a health hazard. If you use infant formula, you should follow the manufacturer’s instructions for use carefully – failure to follow the instructions may make your baby ill. Formula for special medical purposes intended for infants must be used under medical supervision.