Assessment and Management of Patients With Allergic Disorders
The human body is menaced by a host of potential invadersallergens as well as microbial organisms—that constantly threaten its surface defenses. After penetrating those defenses, these allergens and organisms compete with the body for its nutrients and, if allowed to flourish unimpeded, disrupt its enzyme systems and destroy its vital tissues. To protect against these agents, the body is equipped with an elaborate defense system. The epithelial cells coating the skin and making up the lining of the respiratory, gastrointestinal, and genitourinary tracts provide the first line of defense. The structure and continuity of these surfaces and the resistance to penetration are initial deterrents to invaders. One of the most effective defense mechanisms is the body’s capacity to equip itself rapidly with weapons (antibodies) individually designed to meet each new invader, namely specific protein antigens. Antibodies react with antigens in a variety of ways:
(1) by coating the antigens’ surfaces if they are particular substances,
(2) by neutralizing the antigens if they are toxic, and
(3) by precipitating the antigens out of solution if they are dissolved.
The antibodies prepare the antigens so that the phagocytic cells of the blood and the tissues can dispose of them. In some cases, however, the body produces inappropriate or exaggerated responses to specific antigens, and the result is an allergic or hypersensitivity disorder.