SheMy Husband Has Had A Annoying Cough For Over 2mths

sheMy husband has had a annoying cough for over 2mths now. he has consulted with his doctor and has taken copious rounds of antibiotics and the cough still remain and is actually worse. He recently had a cat scan on his chest and they said they can see what looks like scaring and possible pneumonia. He is being referred to a pulmonologist now...anyway, any thought s of what this could be?