there, This is Dr Basu, Experienced Specialist. I am here to address your concerns and provide great service.
There are two possibilities here.
1. recent infection left behind inflammation in his airways causing bronchitis like symptoms. Coughing is common presentation.
2. Mold allergy--reactive airways disease is the term.
Usually coughing is also associated with wheezing and shortness of breath.
Thirdly, there is a possibility of fungal infection of the lungs as well.
Antibiotics only helps partially.
Anti fungal medications are used after confirmation.
I think it is better to take him to the hospital xrays, breathing test to confirm the diagnosis.
The treatment can be planned based on the underlying cause.
A lung specialist also can be consulted with in the hospital.
Best wishes,It was my pleasure to help you today. I am Dr Basu experienced in Lung Diseases.If I have answered all your questions, Please rate my response Excellent (click on the smiley faces) under this chat box only.Please bookmark my profile further questions! This is the link to my profile: http://www.justanswer.com/medical/expert-mysticdoc/