➡️My son is 4 years old , had cold ,cough, fever 3 weeks back ... ➡️After 3,4 days fever subsided , but not the cough and nasal discharge ➡️Doctor prescribed cough expocterant for five days ...2 times after visit of 2 times...but cough is still there . ➡️It looks like post nasal drip ...he is swallowing and then cough starts ...when he sleeps the cough stops but after waking up cough starts again ... ➡️Allergy or post viral cough ? ➡️What should I do to relief from the cough ...?