It is very common for babies to be allergic to formula milk, mainly to milk proteins in formula milk, with varying degrees of severity. 1. Gastrointestinal symptoms, such as crying after drinking milk, refusal of milk, decreased milk consumption, reflux, frequent and prolonged vomiting, diarrhea (watery stool, mucus stool), constipation, blood in stool, abdominal pain and restlessness, etc. 2. Skin symptoms, such as atopic rash, eczema (facial eczema, perioral eczema), urticaria, swelling of the mouth and lips, etc. 3, respiratory symptoms, sneezing, nasal congestion, rhinitis, conjunctivitis, wheezing, shortness of breath, cough, etc. 4, some children have slow weight gain, when the child has the above symptoms, consider protein allergy, seek medical attention as soon as possible, you can test the allergen and total IgE, and pay attention to dietary avoidance, stop ordinary milk powder, choose special medical formula powder feeding, such as oral amino acid milk powder or deeply hydrolyzed protein milk powder, when the symptoms improve gradually transition to partially hydrolyzed protein milk powder. The above are the common symptoms of milk powder allergy in babies, individual tolerance level varies, and the child will show different symptoms.