Question

What is the difference between an allergy and an autoimmune disease? Give an example of each.

Answer 1

Answer:

Allergy: Allergy is an overreaction (exaggerated response) by the immune system to harmless substances that enter the body or come in contact with it. When a person suffers from allergy the immune system exhibits unusual sensitivity towards allergens. Some examples of substances (allergens) that can elicit an allergic reaction are: food products such as milk, nuts, sesame, fish and eggs.

Example: Gluten Allergy: Gluten protein is present in grains and in some inidividuals exposure to gluten proteins causes an allegic reaction. Pollen, house dust mites can also cause allergic reaction.

Autoimmune disease: When an individual is suffering from an autoimmune disorder then the immune system is unable to differentiate between healthy body tissues (self) and foreign antigens (non-self).and body produces antibodies that are directed against body's normal tisses.
Example: Rheumatoid arthritis (disease of joints), Celiac disease (disease of blood and organs, Grave's disease

Difference: In allergy, the immune system reacts to allergens which are extrinsic or outside substances whereas in case of autoimmune disease, the immune system reacts to normal body tissues.