Hi, Noted your history of Hey fever that troubles you in Australia only and not when you are in India, desensitization has not helped, known allergy to dust, dust mites, grass and few more things. In any allergy the basic management is prevention meaning avoid contact with the allergens. This is possible by wet-dusting, vacuum cleaning, avoid contacts as much as possible. Rest of the treatment you already know is antihistamines, steroid when needed. Immunity boosters can help a lot. Take adequate Vitamin A and D after blood tests. Take multivitamins, mineral and trace elements. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon