Milk allergy symptoms, which differ from person to person, occur a few minutes to a few hours after drinking milk or eating milk products.
Immediately after consuming milk, signs and symptoms of a milk allergy might include:
Signs and symptoms that may take more time to develop include:
- Loose stools, which may contain blood
- Abdominal cramps
- Coughing or wheezing
- Runny nose
- Watery eyes
- Itchy skin rash, often around the mouth
- Colic, in babies
Milk allergy or milk intolerance?
A true milk allergy differs from milk protein intolerance or lactose intolerance. Unlike a milk allergy, intolerance doesn't involve the immune system. Milk intolerance causes different symptoms and requires different treatment from a true milk allergy.
Common signs and symptoms of milk protein intolerance or lactose intolerance include digestive problems, such as bloating, gas or diarrhea, after consuming milk or products containing milk.
Milk allergy can cause anaphylaxis, a life-threatening reaction that can narrow the airways and block breathing. Milk is the third most common food, after peanuts and tree nuts, to cause anaphylaxis.
If you or your child has a reaction to milk, tell your doctor, no matter how mild the reaction. Tests can help confirm a milk allergy, so you can avoid future and potentially worse reactions.
Anaphylaxis is a medical emergency and requires treatment with an epinephrine (adrenaline) shot and a trip to the emergency room. Signs and symptoms start soon after consuming milk and can include:
- Constriction of airways, including a swollen throat that makes it difficult to breathe
- Facial flushing
- Shock, with a marked drop in blood pressure
When to see doctor
See your doctor or an allergist if you or your child experiences milk allergy symptoms shortly after consuming milk. If possible, see your doctor during the allergic reaction to help the doctor make a diagnosis. Seek emergency treatment if you or your child develops signs or symptoms of anaphylaxis.