In general, a child’s runny nose when exposed to cold may or may not be allergic rhinitis. Many children may experience the stress symptom of a runny nose as a result of irritation of the nasal mucosa due to sudden exposure to a cold outside environment, which may be a chance phenomenon. Under normal circumstances, it is usually not accompanied by other uncomfortable symptoms. Children with allergic rhinitis, on the other hand, tend to have a runny nose even when they are not exposed to cold air, and this can be accompanied by other uncomfortable symptoms, such as nose itching, sneezing and nasal congestion. If a child has a runny nose when exposed to cold, it is recommended that parents take the child to the hospital in time to identify the cause of the allergic rhinitis and carry out standardized treatment in order to avoid delays in the condition.