Question

What is allergy? Name common allergens that cause allergies in human beings?

Answer 1

Hint:-A healthy body can trigger an immune response whenever it comes across a foreign particle. This foreign particle is known as an antigen. This antigen can be something that most people can consume or be in contact with, however; it might have adverse effects on certain individuals. The immune response triggered can be innate i.e. present since birth or acquired either by artificial means or after an infection.

Complete step-by-step solution:-
The immune system of certain individuals sometimes has an exaggerated response when triggered. The individual may suffer from severe tissue damage. This is known as hypersensitivity. Hypersensitivity is categorized into four types. Type 1 hypersensitivity is called an allergic reaction.
Allergens are the substances that cause this reaction in the body. Immunoglobulin E is the antibody that mediates this reaction. An allergen enters the body and the body starts producing large amounts of Ig E antibody. The Ig E antibody binds to mast cells and basophils. This binding triggers the release of primary mediators such as histamine, heparin, etc., from the mast cells and basophils. The release of the primary mediators causes an inflammatory response. The skin becomes red or airways get constricted, pain, inflammation, sneezing, etc. in certain cases immediate medical intervention is required.
Allergens can be food (say nuts), drugs (say penicillin), or sometimes metals as wells. Some people are allergic to certain animals, or pollen grains.

Note:- Atopic allergy is the type of allergy that is inherited. Certain substances will cause the person to show an allergic reaction. Severe allergic reactions can cause an anaphylactic reaction. There is a full-body reaction that could be fatal. People with asthma and a family history of anaphylactic reactions are at a higher risk.