Allergic Rhinosinusitis is triggered by inhaled aeroallergens like the dust mites, pollen, fungal spores, animal dander etc. The best way to manage it is avoidance of allergens i.e., do regular saline nasal washes to keep your nasal passages free of the allergens before they trigger your immune system to cause your symptoms like sneezing, itchy nose and throat, post nasal drip, runny and stuffy nose.
In addition inhaled and intranasal corticosteroid sprays will soothe the inflamed airways once the symptoms have already been triggered.
Next Steps
Look up videos on saline nasal washes on YouTube to help you do it yourself. Alternatively ask your ENT Specialist to help you out.