Of the three, dust is hardest to avoid-it's everywhere. Wash area rugs. Don't hang sheets and blankets outside to dry. If avoiding hay fever triggers gives you little or no relief, consider trying antihistamines, decongestants, nasal sprays, or eye drops. Antihistamines block the release of histamine, a substance the body automatically produces in response to an allergen.
Histamine is responsible for many allergic symptoms.
For best results, take the antihistamine 30 minutes before going outside. Decongestants reduce nasal blockage by narrowing blood vessels. Your doctor may prescribe other medications, such as cromolyn sodium or steroids. These injections contain only a minuscule amount of allergen. American Institute for Preventive Medicine.