Allergy in Children
Allergic diseases in children traditionally affect the lung (asthma), the skin (atopic dermatitis, the most common form of eczema), and the nasal passages (allergic rhinitis). The following are some interesting tidbits about these illnesses.
* Estimates from a skin test survey suggest that allergies affect 40 to 50 million people in the U.S.A.
* Six million children in the United States have seasonal allergic rhinitis.
* Two million children have atopic dermatitis. This is the most common skin condition in children under eleven years of age.
* Allergies have a strong genetic predilection. The likelihood of a child developing allergic disease is 1 in 4 if one parent has allergies and 2 in 3 if both parents have allergies.
Allergies may be seasonal or chronic depending upon the exposure to the allergen. An allergy may be influenced by factors such as emotional stress, fatigue, infection, air pollution, and weather changes that can cause day to day variation in the severity of symptoms. These triggering factors add to what doctors call the “allergic load,” the amount of allergens the body can tolerate at any given time without the occurrence of symptoms.
Allergy tests may be of two general types. In vivo tests that measure the immune response to an agent called an allergen that induces an allergic (atopic) reaction, and in vitro tests that measure the antibodies that mediate an allergic response. Such antibodies are those of the immunoglobulin E class (IgE) which have epsilon heavy chains which attach to mast cells.
Allergy tests are performed to determine the cause of a person’s allergic reaction. An allergic reaction is caused by the production of specific IgE antibodies against one or more antigens. Those antigens that elicit IgE production are termed allergens and are usually harmless substances.