PATHOLOGY

Detailed explanation-1: -Allergies occur when your immune system reacts to a foreign substance-such as pollen, bee venom or pet dander-or a food that doesn’t cause a reaction in most people. Your immune system produces substances known as antibodies.

Detailed explanation-2: -An allergen is a substance that can cause an allergic reaction. After being exposed to a substance such as bee sting venom, the person’s immune system becomes sensitized to it.

Detailed explanation-3: -Food allergies occur when the body’s immune system reacts to certain proteins in food. Food allergic reactions vary in severity from mild symptoms involving hives and lip swelling to severe, life-threatening symptoms, often called anaphylaxis, that may involve fatal respiratory problems and shock.

Detailed explanation-4: -Your immune system produces antibodies that detect the allergen and cause inflammatory reactions and the release of a chemical called histamine. Histamine causes hay fever symptoms, such as itchy and watery nose and eyes, and sneezing.