I need help regarding my son he is six year old. From 1.3 year he always has mucus coming out of his nose and on/off cough . I visited every doctor possible in my town they always gave a antibiotic and cough syrup but there is no relief in symptoms , one doctor told for allergic rhinitis and gave nasal sprays but that too don't worked. Now I am in a state of helplessness. As not even a single day in past 1.3 years he is free form nasal congestion and cough follows it . I need consultation if it is treatable or what is it? Please help me