An allergy is an abnormal immune response or increased sensitivity, to substances known as allergens which are usually proteins. Non-allergic triggers include temperature or barometric pressure changes or odors/irritants such as cleaning agents, fragrances/potpourris, tobacco smoke or vehicle exhaust to name a few. A person with allergies experiences symptoms when exposed to common allergens such as tree, grass, ragweed pollen, cats/dogs and dust mites that correlate with allergy testing. A non-allergic person would respond to irritants and weather changes and allergy testing would be negative. Both allergic and non-allergic rhinitis are very important conditions that need to be differentiated from one another as the treatment of these conditions is quite different from one another.