IMMUNOLOGY

Detailed explanation-1: -An allergen is a substance that can cause an allergic reaction. In some people, the immune system recognizes allergens as foreign or dangerous. As a result, the immune system reacts by making a type of antibody called IgE to defend against the allergen. This reaction leads to allergy symptoms.

Detailed explanation-2: -Common allergy triggers include: Airborne allergens, such as pollen, animal dander, dust mites and mold. Certain foods, particularly peanuts, tree nuts, wheat, soy, fish, shellfish, eggs and milk. Insect stings, such as from a bee or wasp.

Detailed explanation-3: -When a harmless substance such as dust, mold, or pollen is encountered by a person who is allergic to that substance, the immune system may over react by producing antibodies that “attack” the allergen. The can cause wheezing, itching, runny nose, watery or itchy eyes, and other symptoms.

Detailed explanation-4: -An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies.

Detailed explanation-5: -An allergy occurs when the body’s immune system sees a substance as harmful and overreacts to it. The substances that cause allergic reactions are allergens. When someone has allergies, their immune system makes an antibody called immunoglobulin E (IgE). These antibodies respond to allergens.

Detailed explanation-6: -The correct answer is: An overreaction from the immune system to a foreign substance. Explanation: Allergies are an overreaction from the body’s immune system to foreign substances called allergens.