This is an allergic reaction that a large number of individuals have when they are exposed to pollen and it is commonly known as allergic rhinitis that is seasonal for many people. There are some however, that can suffer from symptoms of this type of allergy all year round. For those that suffer from seasonal allergies, it is caused from the male reproductive system of plants as well as microscopic particles that are generally found in the air we breathe during the spring and summer from the pollination process of weeds, with ragweed being one of the biggest problems, various grasses, mold, and trees. For the individuals that suffer from this type of allergy the whole year round, it is generally caused from particles that are found to be present in the air no matter what time of the year it may be. Some of the biggest culprits for bringing on the bothersome symptoms that individuals suffer from the irritants that they contain would include animal dander, feathers, pillows, mold, dust mites, clothing made with down, upholstery, draperies, bedding, and even thick bedding. Symptoms can include itching, running nose, sinus inflammation causing redness and swelling, and sneezing.