You may try this if you don't have any associated problem like sinusitis
of upper respiratory tract.
1) flomist nasal spray - 1 puff in each nostril twice a day (after getting up at morning and washing nasal canal as much possible ant at night around 8 pm.) for 3 month.
2) ifiral nasal spray - 1 puff in each nostril 6 hourly (4 times a day) for 1 month. Then 8 hourly (3 times a day) for 1 month, then twice daily for 1 month.
3) desloratadine - 5 mg tab - 1 tab at 8/9 pm daily for 1 month. Then desloratadine 2.5 mg 1 tab at night for 15/20 days more. Then stop. If symptom comes back back take 2.5 mg daily again and continue for another 15 days.
Report back after 3 month while on medicine. Keep this prescription copy for my reference if you come back after 3 months. Remember, it takes long time to desensitise your nose's mucous membrane.