My 15 year old son has had an intermittent forceful cough for about a year. He coughs every day. Other things we have noticed is that his saliva is VERY thick and we can always tell which glass he has used because where he holds the glass gets crusty feeling and it s not from food, only other thing is that he has started to sweat profusely. He is a healthy 6 1 who plays sports right now cross country and helps his dad with farm chores. An ent checked his bronchial tubes and said they were pristine. A pulmonary Dr had him try a few different inhalers and none of them made any difference. Our pediatrician ordered an upper GI study and it came back fine.