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

Q : 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.

Answer: Friend did not feel an allergic reaction.with the first initial contact: An allergic reaction occurs when the immune system overreacts to a harmless substance (an allergen).The immune system protects the body from infections and diseases. In some people, substances such as pollen, dust mites, insect stings etc, are allergens that trigger the production of antibodies (Immunoglobulin E - IgE). These antibodies travel to cells that release chemicals causing symptoms (usually in the nose, lungs, throat, on the skin & other minor symptoms). An allergic reaction may not occur the first time a person is exposed to an allergy-producing substance (allergen)

If / when your friend comes in contact with antigen a second time: The person is then sensitized to the allergen and any  future exposures ( i.e. second time or even any minor exposure) to this allergen produces an allergic reaction.