Hello dear
Warm  welcome to Healthcaremagic.com
I have evaluated your query in details  .
*  You have been diagnosed correctly as 
allergy to dust giving irritation of
    upper 
respiratory tract mucosa and itching .
*  Medicines are supportive only , the thing is avoidance of the allergen by
    using face mask , avoiding exposure to pollens .
*  Gargles with salted lukewarm water added peppermint oil , herbal 
    support with honey , turmeric , bassil leaves are best .
Hope this clears your doubt  .
Wishing you fine recovery .
Welcome for any further  assistance .
Regards  take care .
Dr. Bhagyesh ( MS , FMAS - consultant surgeon )