 [ Symptoms ] does ibuprofen pmr interact with any other medications [ Disease ] a cough in a healthy 4 year old can be many things most commonly colds from viral infections can cause coughs other causes can be allergies post nasal drip and asthma if your child has had the cough for several weeks it is important to speak to your doctor if he has allergies or asthma that is causing this there are medications available to make him feel better call your doctor