A student on a school trip started sneezing and wheezing soon after reaching the hill station for no explained reasons. But, on return to the plains the symptoms disappeared. What is such a response called? How does the body produce it?
The response such as sneezing and wheezing for no explained reason is called allergy and the substance against which the immune system shows such exaggerated response is called allergen.
Body produces IgE type of antibody against allergens as a response. Most common type of allergens are pollen grains, dust, etc.