What Are Allergies?
One of the marvels of the human body is that it can defend itself against harmful invaders such as viruses or bacteria. But sometimes the defenses are too aggressive, and harmless substances such as dust, mold or pollen are mistakenly identified as dangerous. The immune system then rallies its defenses, launching a host of complex chemical weapons to attack and destroy the supposed enemy. In the process, some unpleasant and, in extreme cases, life-threatening symptoms may be experienced by the allergy-prone individual.
What Are the Causes of Allergic Reactions?
There are hundreds of ordinary substances that can trigger allergic reactions. Among the most common are plant pollens, molds, household dust (dust mites), animal dander, foods, medicines, feathers and insect stings. These triggers are called “allergens.” An allergic reaction may occur anywhere in the body, but usually appears in the skin, eyes, lining of the stomach, nose, sinuses, throat and lungs – places where special immune system cells are stationed to fight off invaders that are inhaled, swallowed or come in contact with the skin.
Who Develops Asthma and/or Allergies?
Asthma and allergies can affect anyone, regardless of age, gender, race or socioeconomic factors. While it is true that asthma and allergies develop more commonly in children, they can occur for the first time at any age or, in some cases, recur after many years of remission. Although the exact genetic factors are not yet understood, the tendency to asthma and allergies is linked to heredity. In susceptible people, factors such as hormones, stress, smoke, perfume or other environmental irritants may also play a role.