My 7 year old son has had a chronic dry cough for about 2 1/2 months. i gave him singular did not work, he had chest xrays all good, lungs sound great, they did a "whooping cough test" negative. cough meds do not work. no fever, acts like a healthy 7 year

The : The cause of a chronic cough can be a very tricky problem to figure out in kids or adults. Common causes include: -asthma -gastro-esophageal reflux -allergies -chronic sinusitis -pertussis (whooping cough) -habit cough -pneumonia or other infectious cause such as tuberculosis it looks like your son's doctor has been doing a good job thinking of these problems and trying to rule out each one with the tests and medication trials they have been suggesting. Most of these problems will cause coughing all night as well as during the day except for habit cough. I've attached a website with some information on habit cough which is very common in kids. I hope this helps.