Allergies and Autoimmunity

People might have often witnessed a sudden unease like sneezing, coughing, itchy eyes, running nose, wheezing or asthma when they travel to a new place or enter new surroundings. However, they fade away as soon as they come back. This is a reaction of the body to the changing environment. In this section, we would discuss allergies and autoimmunity.


Our body is sensitive to certain particles in the surroundings. This hypersensitivity of the immune system to certain antigens in the environment is called allergy. The antigens which cause the allergy are called allergens. Certain features of them are explained below:

  • Common allergens include pollen, dust, feathers, animal dander, mites, latex and even certain food.
  • The symptoms of allergies include sneezing, coughing, itchy eyes, running nose, itchy rashes, red eyes, difficulty in breathing and swallowing.
  • Allergies are caused due to the release of chemicals such as histamine and serotonin.
  • In response to the allergens, our body produces antibodies called immunoglobulin E antibodies (IgE).
  • Antihistamine, adrenaline, and steroids are the few drugs which are given to reduce the symptoms of allergy.
  • In severe reactions, adrenaline- hormones released by the adrenal glands, most commonly known as epinephrine, is injected into the body.
  • An allergy to at least one allergen is very common throughout the world.
  • However, with the modern lifestyle, people are more prone to allergies due to low immunity and high sensitivity to the environment.


Organs of the Immune system

Autoimmunity is the response of the immune system of an organism in which it attacks its own healthy cells and tissues. A disease which results due to this kind of response is called an autoimmune disease. The higher vertebrates are capable of recognizing foreign antigens. Due to the memory-based acquired immunity, their immune system could very well distinguish between their own cells and the foreign organisms. However, due to genetic or some unknown reason the body attacks its own cells and causes autoimmune diseases. The most common example of an autoimmune disease is rheumatoid arthritis (RA). Others are Addison’s disease, Graves’ disease, polymyositis (PM), etc.

Similarities Between Allergies and Autoimmune Disease

The main similarities between the two are:

  • Both the allergies and autoimmune diseases cause some sort of redness or swelling, due to the higher immune response.
  • Itching is a common symptom of both Allergies and autoimmune diseases.
  • Both symptom results in a general feeling of fatigue and sickness

Differences Between Allergies and Autoimmune Disease

The main difference between the two are:

  • The allergies are mainly caused by an external trigger such as pollens, certain foods, etc.
  • Autoimmune diseases are the result of an internal trigger to our own body’s cells.

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Practise This Question

State whether True/False:
Activated mast cells with IgE antibodies release histamine.