The most common symptoms of cow's milk allergy include eczema or skin rash, abdominal pain or cramps, vomiting or diarrhea and in some cases, excessive crying. Less commonly, some children may have a very serious allergic reaction called anaphylaxis. This reaction usually occurs within minutes after eating or drinking food to which they're allergic. The most serious symptom of an anaphylactic reaction is the swelling of the face, mouth and tongue leading to difficulty breathing. If a child ever has these symptoms, medical help should be sought immediately.
Untreated anaphylaxis can quickly become fatal.
Fortunately, anaphylaxis is rare. There are two very important reasons for confirming that a child actually has a milk allergy. First, cow's milk allergy is not the only cause of the symptoms described above. These symptoms can be caused by other conditions, which would need a different treatment. The second reason is because of the danger of an anaphylactic reaction.