Predisposition

 

Allergic diseases are multifactorial 
Clinical symptoms are the only obvious part of the allergic process, "the tip of the iceberg". The allergic process is based on a genetic predisposition of the individual to become sensitized, to develop inflammation and organ irritation manifested as hyperresponsiveness. Sensitization, inflammation and irritation of tissue may develop differently in individual patients, subsequent to different exposures. Such reactions may express themselves as very different levels of symptoms.

 

Obtaining a family history is important in evaluating patients and interpreting test results. For children in families where both parents have similar allergy symptoms, the risk for becoming allergic is about 70% (1); the risk is lowered if just one parent is allergic. Genetic factors determine how easily and strongly the individual will become sensitized and how much IgE antibodies will be produced (2).

 

In addition, genetics will influence the degree of inflammation after exposure to a certain amount of allergen, as well as how reactive the individual will be when exposed to various allergens and irritants (i.e. if the tissue is easily irritated and hyperresponsive).