1. What is a baby’s milk powder allergy? Baby milk powder allergy refers to a series of symptoms caused by a baby\’s allergy to milk proteins, including skin itching, redness and swelling, shortness of breath, etc. This type of allergy usually occurs when babies are fed milk powder, because milk powder contains ingredients such as milk protein or whey protein, and these ingredients are the main causes of allergies. 2. What are the symptoms of baby’s milk powder allergy? 1. Itchy skin: Babies may experience symptoms such as skin redness, swelling, blistering, and severe eczema. 2. Shortness of breath: Babies may suffer from shortness of breath and asthma.