Hay Fever (Allergic Rhinitis)
Hay Fever, or Allergic Rhinitis, is an allergic inflammation of the nasal airways (airways of the nose). Hay fever occurs when an allergen, or substance that causes allergy, such as pollen or dust is inhaled by an individual with a sensitized immune system, because it triggers antibody production. These antibodies mostly bind to cells (mast cells) that contain a substance called histamine. When the mast cells are stimulated by pollen and dust, histamine and other chemicals are released. This causes itching, swelling, and the production of mucus (a slippery secretion produced by, and covering, mucus membranes).
Symptoms vary in severity between individuals. Very sensitive individuals can experience hives, a skin rash with dark red, raised, itchy bumps that are often, but not always caused by allergic reactions) or other rashes. Particles in polluted air and chemicals, such as chlorine and detergents, can greatly aggravate the condition.