Hi thanks for contacting HCM...
Your child needs detail examination and investigation ..
Repeated viral or allergic infection can lead chronic cough....
Auscultation of your baby done...
If rhonchi heard it could be 
bronchiolitis or asthma like condition....
Try to avoid exposure to dust, pollen , 
passive smoking etc....
Healthy food given ...
Give him turmeric powder one tsp added hot milk daily for drinking....
Sputum examination or culture needed to rule out 
whooping cough by bordetella petusis....
According to sensitivity report treatment given ....
If needed chest x ray also done...
For excess cough antitussive medication can be given...
Consult pediatrician with keeping this in mind.
Take care ...