What causes hives in babies? If your baby has hives for the first time, they are usually caused by allergies, such as: medications: e.g. antibiotics, cold medicine or aspirin; foods: e.g. eggs, nuts, seafood; touching certain objects: e.g. plants, animals or some latex, mosquito bites. In addition to allergies hives can also be caused by infections or exposure to cold air and cold water. If you find that your baby’s hives are related to certain food or drug allergies, then try to avoid them. What is the need to see a doctor for hives in babies? Urticaria in babies usually goes away on its own, and good care to stop the itching is sufficient, but if the following conditions occur, you should seek medical attention; your baby has more severe hives or itching; your baby has angioneurotic edema; your baby has a severe allergic reaction: difficulty breathing, nausea and vomiting, abdominal pain.