The inside of your nose has a lining that helps to warm and moisten the air before it enters your lungs. The mucus in the lining also helps to filter out dust and other particles in the air. When allergy-causing pollen becomes trapped in the mucus, it touches special cells, which make histamine. The histamine makes your nose run and your eyes water. It can also make you sneeze. Your doctor may prescribe antihistamines to make you feel better.