 [ Symptoms ] is there a test to tell if mono is gone  my son is 17 and has mono he was sick for a couple of week before it was determined that he had mono no it has been 4 weeks and he is feeling great is there a way to tell if he still has mono or can he go back to full daily activities [ Disease ] two common reasons for three year olds to have a on going cough undiagnosed asthma and day care attendance if you have a family history of allergies or asthma asthma should be carefully investigated constant runny noses can trigger a cough as well if your child is in day care preschool or going to play groups she is constantly exposed this time of year to back to back viral infections this alone can mimic asthma and cause a chronic cough