Talk to Pediatrician on Cough And Strange Sneezing

I have 5 years old son.He was living with me outside the country and last year I settled my family in Pakistan .In Pakistan he always having cough and throat issue and always some tumer in his throat case cough.I feel just because of pollution he face all this because when he came outside country then no issue but in Pakistan cough.which doctor I have to consult for him because all doctors have anti biotic but after 15 days same issue again.I need permanent solution.