Milk allergy symptoms, which differ from person to person, occur a few minutes to a few hours after you or your child drinks milk or eats milk products. Immediate signs and symptoms of milk allergy might include: 
Hives
Wheezing
Itching or tingling feeling around the lips or mouth
Swelling of the lips, tongue or throat
Coughing or shortness of breath
Vomiting
 Signs and symptoms that may take more time to develop include: 
Loose stools or diarrhea, which may contain blood
Abdominal cramps
Runny nose
Watery eyes
Colic, in babies
 Milk allergy or milk intolerance? A true milk allergy differs from milk protein intolerance and lactose intolerance. Unlike milk allergy, intolerance doesn't involve the immune system. Milk intolerance requires different treatment from 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. Anaphylaxis Milk allergy can cause anaphylaxis, a life-threatening reaction that narrows the airways and can 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 health care provider, no matter how mild the reaction. Tests can help confirm milk allergy, so you can avoid future and potentially worse reactions. Anaphylaxis is a medical emergency and requires treatment with an epinephrine (adrenaline) shot (EpiPen, Adrenaclick, others) and a trip to the emergency room. Signs and symptoms start soon after milk consumption and can include: 
Constriction of airways, including a swollen throat that makes it difficult to breathe
Facial flushing
Itching
Shock, with a marked drop in blood pressure
