If the 5-month-old baby has a clear runny nose caused by a cold, he can take pediatric aminophenol xanthamin granules, etc. If it is allergic rhinitis, prevention should be the main focus, and desensitization treatment should be carried out to determine the allergens. 1. Colds: 5-month-old infants with colds will have symptoms of running nose, accompanied by nasal congestion, sneezing, fever, cough and so on. Can follow the doctor’s instructions to take children’s cold granules to relieve cold symptoms, at the same time can use physiological sea saline nasal spray nasal rinse nasal cavity, reduce nasal secretions and other comprehensive treatment. 2. Allergic rhinitis: 5-month-old babies run a clear nose may be allergic rhinitis, this disease is often due to cold air stimulation, or pollen, dust, food and drugs and other allergens stimulation. It can also be accompanied by frequent sneezing and other symptoms. However, since infants and young children are too young to use hormonal medications applied to the nose, the main focus is on symptom control and prevention. If allergens are identified, they can be treated by desensitization to avoid recurrent allergic rhinitis. At the same time to maintain air circulation in the baby’s room, try to avoid taking the baby out in the spring and fall seasons, wear a mask when you go out, go out and come home, you must promptly use saline for nasal spray in order to clean the allergens absorbed in the nasal cavity, and do a good job of protecting the baby. 5-month-old infants running clear nose need to be by the doctor to comprehensively determine the cause of the disease, standardized treatment. The above drugs need to follow the doctor’s instructions to use, avoid self-medication.