Which of the following chemical is released during allergic reactions?

Correct option is B

Ans. (b)
During allergic reactions, histamine is released by mast cells and basophils as part of the immune response. This chemical is responsible for causing symptoms like itching, swelling, redness, and increased mucus production.
Information Booster
1. Histamine's Role:
· Dilates blood vessels (vasodilation).
· Increases permeability of capillaries, leading to swelling and redness.
· Stimulates nerve endings, causing itching.
2. Antihistamines: Medications used to counteract histamine’s effects during allergic reactions.
3. Hapten: A small molecule that becomes allergenic only when bound to a protein carrier.
4. Heparin: Prevents blood clotting but has no direct role in allergic reactions.
5. Sulphuric Acid (H₂SO₄): A strong acid used industrially, unrelated to allergies.