Question

A friend of yours recently said they came in contact with an antigen that is known to cause an allergic reaction based upon a family history. However, your friend says they did not feel an allergic reaction. You believe though your friend will suffer an allergic reaction if they come in contact with the antigen again. Please discuss what happened with your friend with the first initial contact and what will happen if/when your friend comes in contact with antigen a second time. Be thorough as possible.

Answer 1

The immune system when first exposed to an allergen produces a type of antibody called immunoglobulins E, IgE. This IgE binds to a type of WBC called basophils in the bloodstream and mast cells in the tissue. The first exposure by a person to allergen make him sensitive to the allergen which is called sensitization but does not cause any symptoms. When the sensitized person subsequently encounter the allergen, the basophils and mast cell with IgE on their surface release substances such as histamine, prostaglandins and leukotrienes that cause swelling or inflammation in the surrounding tossues. Such substances begin a cascade of reactions that continue to irritate and harm tissues and the reactions can be mild or severe.