In cow's milk allergy (CMA) the immune system mistakenly identifies a protein in cow's milk as harmful and triggers an allergic reaction. This leads to a range of symptoms that can vary in type, severity and time of onset from baby to baby.

The symptoms of CMA and the severity of the reactions are wide ranging. They can include colic, skin reactions (such as a red itchy rash, eczema or swelling of the lips, face and around the eyes), digestive problems (such as vomiting, abdominal pain or diarrhoea) and hay fever-like symptoms (such as sneezing or itchy, blocked or runny nose). Symptoms can range from mild to severe reactions.

These symptoms can either appear immediately after consuming dairy (within minutes or up to two hours) or may be delayed, taking a few hours or up to a few days to develop. Babies with CMA may have a mixture of both 'immediate' (usually IgE-mediated) and 'delayed' (usually non-IgE-mediated) symptoms. Symptoms may also lead to night-time waking, crying or distress during feeding, or poor weight gain. Find out more about the different types of cow’s milk allergy

Immediate symptoms
(usually IgE-mediated)
Can appear within minutes or up to two hours after eating a food containing cow’s milk protein and may include:
Swollen lips, tongue or face
Hives, rash, redness, itching or swelling
(Raised, red and often itchy bumps on the skin that could stay in one area or spread. Swelling under the skin)
Eczema flare up
(Sudden triggering of red, itchy, and cracked skin)
Hay fever-like symptoms
(Sneezing or an itchy, runny or blocked nose. Eye inflammation)
(Frequent, loose and watery poos)
Tummy pain
(Being sick)
Breathing difficulties
(Coughing, chest tightness, wheezing or shortness of breath)
Anaphylaxis seek emergency help immediately
(Includes sudden and severe breathing problems, fast heartbeat and itchy raised rash)
Delayed symptoms
(usually non-IgE-mediated)
Can appear within a few hours or up to a few days after eating a food containing cow’s milk protein and may include:
Colic-type symptoms
(Excessive and frequent crying)
(Spitting up during or after feeds)
Eczema, itching or redness
(Red, itchy, or cracked skin)
Tummy pain
(Painful wind)
Food refusal
(Less frequent poos and discomfort when trying to poo)
Unusual stools
(Frequent or loose poos or poos that contains blood or mucus)


Please be aware that this is not an exhaustive list of CMA symptoms. Some of these symptoms can also occur for reasons other than CMA, so it is important to discuss them fully with your doctor.