A 9-year-old boy is stung on the arm by a wasp and very rapidly develops redness and swelling at the site of the sting. Which of the following substances is most responsible for these early changes?

Question

Quizplus · Accepted Answer

Histamine is released by mast cells and basophils in response to an allergen or injury, leading to rapid vasodilation and increased vascular permeability, causing redness and swelling at the site of the sting.

A 9-Year-Old Boy Is Stung on the Arm by a Wasp