My 3.5 year son , have persistent cough for last 2 months, doctors 1st gave levolin and allergy syrup, had stopped both medicine after few days, But coughing persisted again, was trying some home medicine, but cough further worsen , took to doctor which was told he got some chest infection with fever, gave dexofen, told levolin to continue and also allergy medicine for 7 days. but again got fever on 5th day, took to doctor he said its viral, and all chest infection got cleared, told to continue levolin if cough occurs , and also allergy syrup for 1 month. but from yesterday again he got running nose & cough, from today again started levolin. Please suggest