My son's age is 5. He has dust allergy normally he starts to cough a lot but in india doctor used to give Allegra and it used to work. Last 5 months back shifted to London. For the last 15 days onwards, he is constantly coughing but very less during the night time but the coughing increases after having any food or milk. The doctors are saying the chest is clear and has given ventilin evohaler.