During an allergic response, sensitized cells produce in abnormal quantities when an allergen reappears after an initial exposure?

During an allergic response, sensitized cells produce in abnormal quantities when an allergen reappears after an initial exposure?

• A. Antihistamines
• B. Histamine
• C. Toxins
• D. Lysins

Answer: (B)

When a person who has been sensitized with an allergen is re-exposed, mast cells (and basophils) that carry IgE on their surface become activated and release histamine in large amounts. This histamine release is what drives the immediate allergic symptoms, such as swelling from increased vascular permeability, itching, and bronchoconstriction. Antihistamines are drugs that block histamine’s effects rather than being produced by the body during the reaction, while toxins and lysins are not involved in the allergic mediator release process.

When a person who has been sensitized with an allergen is re-exposed, mast cells (and basophils) that carry IgE on their surface become activated and release histamine in large amounts. This histamine release is what drives the immediate allergic symptoms, such as swelling from increased vascular permeability, itching, and bronchoconstriction. Antihistamines are drugs that block histamine’s effects rather than being produced by the body during the reaction, while toxins and lysins are not involved in the allergic mediator release process.