Milk protein allergy in newborns may present skin symptoms such as rash, gastrointestinal symptoms such as abdominal distension and diarrhea, as well as respiratory and cardiovascular symptoms. 1. Skin symptoms: Milk protein allergy is a common symptom in newborns, which may include skin rashes on the face and trunk. 2. Gastrointestinal symptoms: when newborns are allergic to milk protein, it may cause digestive symptoms, such as vomiting, bloating, diarrhea, etc., and severe dehydration, drowsiness and other symptoms. In addition, neonatal milk protein allergy can also appear respiratory system, cardiovascular system and other symptoms, such as laryngeal edema, lower respiratory chest tightness, irritating cough, croup, respiratory arrest and so on. As milk protein allergy in newborns can cause various uncomfortable symptoms, it may lead to unexplained crying in newborns. When newborns have similar symptoms of milk protein allergy, they need to consult the doctor for a clear diagnosis and timely and targeted treatment, so as not to miss the opportunity for treatment.