Chapter 21.6, Problem 27BYGO

Summary Introduction

Introduction:

Hypersensitivity is an abnormal and harmful reaction toward an antigen. It includes alloimmunity (reaction to transplanted tissues from another person), autoimmunity (reaction to one’s own tissues), and allergies. Allergies are reactions to an antigen, which is from the environments. Such environmental antigens are known as allergens, which occur in pollen, dust, mold, vaccines, wasp venom, bee, animal dander, poison ivy, and foods such as milk, nuts, egg, shellfish, and some plants.