Chapter 7, Problem 11LO

Summary Introduction

To describe: The course, effects, and complications of HIV/AIDS.

Concept introduction: Overreaction of the immune system toward the normally harmless substances is known as allergic reaction. The causative agent or any substance that causes allergy is called an allergen. The common allergen includes chemical or drug and food or pollen from a plant. Re-exposure of the same allergen immediately stimulates the IgE to bind to the sensitized mast cells and release chemical mediators such as histamines from the mast cell granule to cause allergic reactions.