Irrigating the nose with saline solution (salt water) may help soothe upper respiratory allergies by removing irritants that become lodged in the nose and cause inflammation. In fact, saline solution may even wash away some of the inflammatory cells themselves.
You can buy ready-made saline solution at your local drugstore, or you can make your own fresh solution daily by mixing a teaspoon of salt in a pint of warm, distilled water and adding a pinch of baking soda. Bend over a sink and sniff a bit of solution into one nostril at a time, allowing it to drain back out through the nose or mouth; do this once or twice a day. (If you also have asthma, however, check with your doctor before trying this remedy.)