The main ingredient of Benadryl is acetaminophen, which is a non-steroidal anti-inflammatory drug with good antipyretic as well as analgesic effects. Acetaminophen is mainly used for fever and can be given when a child’s body temperature is above 38.5 degrees. If a child has a headache, toothache or muscle pain, Benadryl can also be used for analgesic treatment. However, it is important to pay attention to the following points when applying Benadryl, because this drug is symptomatic and it is recommended that the duration of application should not exceed 5 days. If the child is allergic to aspirin, it should be used with caution. If the child’s liver and kidney function is not good, the amount should not be too large and should be applied strictly according to the instructions.