a few questions I would like to ask first: does this cough happens at night ? early night or middle of the night ? does he has skin allergies? runny nose ? any body in family had asthma or hyperresponsive airways ? does he snores when he s a sleep ? well , the most common cause of Cough in children is post nasal drip , from adenosinusitis or allergic rhinosinusitis, if he doesn t snore at sleep or have a runny nose all the time then the possibility of these conditions are low . the second most common is for sure is asthma , which can be assessed by careful physical exam and history , a chest XRAY would be helpful in this case to role out other causes , like pneumonia or foreign body inhalation . the fact that your child slightly improved on Asthalin suggests asthma , but in order to control it , we need something called controller medication , it s an inhalational steroids , it s very important to start him on it if he really have asthma , you can start with floxitide inhaler 125 Mcg twice daily for 3 months , it s minimally absorbed in the system and rarely if ever have a systemic side effects. I hope this helps