Nine-month-old babies with allergies if the allergy symptoms are mild is mainly to avoid possible allergens, continue to observe the allergy symptoms can be, if the allergy symptoms are obvious usually need to take anti-allergy drugs, such as oral loratadine or cetirizine hydrochloride and so on. If you have hives, you can use topical budesonide ointment or glycerite lotion to reduce the symptoms, and if you have gastrointestinal symptoms, it is usually a symptomatic supportive treatment. If the allergy symptoms are severe, especially with neurovascular edema, you should go to the pediatric emergency department of the hospital as soon as possible while taking oral anti-allergy medications, and if necessary, you may need to take oral or intravenous hormonal anti-allergy treatment. Allergies should be carefully searched for possible allergens, and if necessary, allergen screening should be done in the hospital. Only by avoiding the ingestion of or contact with allergens as much as possible after the allergens are detected, can allergic symptoms not recur.