If you think your baby might be showing signs and symptoms of cow’s milk allergy, make an appointment to see your baby’s doctor. While you’re waiting to see him or her, start keeping a diary of your baby’s symptoms using our symptoms diary to jot down the symptoms you notice, and whether they flare up during or after feeds or at certain times of day. It’s a good idea to keep track of this over 1–2 weeks. It’s also essential to indicate which foods your baby’s consuming – whether it’s breast milk, formula or solids. Then take this diary to your baby’s doctor to help you discuss your concerns together and help to reach a diagnosis.

Skin Reactions

Itchy red rash, hives (raised, red and often itchy bumps that could stay in one area or spread through the body), or swelling of the lips, face and around the eyes.

Nausea or Vomiting

Babies could feel sick or might projectile vomit.


A breastfed baby’s stools are usually runny while a formula-fed baby’s stools tend to be a little thicker. If your baby has diarrhea, you’ll notice frequent, watery, foul-smelling and loose stools. You should contact your doctor or health visitor if your baby gets diarrhea, as they could quickly become dehydrated.

Hay Fever-like Symptoms

Sneezing and an itchy, runny or blocked nose.

Breathing Difficulties or Wheezing

Coughing, chest tightness, wheezing and shortness of breath.


Anaphylaxis (anaphylactic shock) is the most serious possible allergic reaction – it comes on quickly, affects the whole body, and is potentially life-threatening. Signs include breathing difficulties, becoming faint, skin irritation and swellings, especially of the face. Fortunately, this type of allergic reaction is uncommon in infants. If you suspect anaphylaxis, call 911 for an ambulance immediately!


Colic is the medical term used to describe excessive, frequent crying in babies who otherwise appear to be healthy and well. The crying is usually very intense, and the baby’s face might be red and flushed and they may clench their fists, draw up their knees or arch their back. This tends to follow a pattern of threes – crying for more than 3 hours a day (usually in the evening), for more than 3 days a week, and for more than 3 weeks.

Skin Reactions/Eczema

Skin is red, itchy, dry and cracked. It often affects areas with skin folds, such as behind the knees, the inside of elbows, the side of the neck and around the eyes and ears.


Reflux is where the contents of the stomach come back up towards the mouth. It's sometimes called "spitting up." Almost all babies get this to some extent, but in severe cases, babies can regurgitate lots of liquid, vomit forcefully, choke or gag, arch away from the bottle or breast, seem irritable during or after feeds, or have trouble putting on weight.

Unusual Stools

Babies with cow’s milk protein allergy may have loose or frequent stools, and there could also be blood and/or mucus in their stools. The blood could be due to bleeding around their bottom, or from their bowels, and it’s important to speak to your doctor to find out what’s causing this bleeding.

Abdominal Pain

Babies could get severe cramping or pain in their tummy area, and might arch their backs.


The stools of a constipated baby might look like little rabbit pellets or hard balls. Your little one might go several days without producing anything or the stools can be difficult to pass. You may also notice some blood. Don’t judge whether your baby is constipated by how frequently they have a bowel movement – sometimes, infants can be healthy and go several days without one.

Failure to Thrive

This is when babies don’t gain enough weight. They might be lethargic, have a poor appetite or show developmental delays.