Allergies and allergic reactions are still heavily researched today. Some question whether allergies could be considered an autoimmune disease. Recent studies show some associations between allergies and autoimmunity.
In this article, we’ll compare how the body reacts to an allergic reaction and autoimmune response. We’ll also identify key differences between these responses.
What Are Allergies?
Allergies, also known as hypersensitivity reactions, are defined as an abnormal or inappropriate response of the immune system to a normally harmless substance.
For example, pollen is a harmless substance found outdoors. However, someone with a pollen allergy may experience symptoms such as sneezing, watering eyes, congestion, itchy skin, and rashes. This is because the immune response perceives pollen as a harmful substance.
Allergic reactions range in severity. While some reactions are quite mild others can be life-threatening and need medical treatment.
Doctors base an allergy diagnosis on symptoms from skin tests to identify allergens. If an allergy is discovered, it’s recommended to avoid the substance. You can also receive allergy shots to desensitize you to the allergen.
How Do Allergies Develop?
When a person is first exposed to an allergen, they do not experience a reaction. Upon the first contact, the immune system produces immunoglobulin E or IgE. This is an antibody that binds with cells called basophils, found in the blood.
At the time of the second exposure to the allergen, the person will experience symptoms. The basophils and mast cells with IgE release chemicals such as histamine and prostaglandins.
These trigger the common symptoms of an allergic reaction including:
- Inflammation of tissues
This reaction can be mild or severe.
A variety of substances can trigger an allergic reaction. Some of the most common allergens include environmental factors, animals, and food.
Food allergies are becoming a major problem in the United States. Many people are allergic to shellfish, peanuts, fish, cow dairy, soy, wheat, oats, and sesame.
About Autoimmune Diseases
23 million Americans suffer from autoimmune diseases. Of these millions, 80% are women.
The immune system is the body’s defense mechanism against bacteria and viruses. It identifies invading microbes and cells and attacks them.
An autoimmune disease means the immune system attacks its own organs and tissues. It mistakenly perceives the body’s own cells as dangerous and attacks them.
For example, someone with type 1 diabetes has their pancreatic cells attacked. Someone with rheumatoid arthritis has their joints attacked by their immune system.
Autoimmune diseases often affect multiple organs and are often difficult to identify.
For example, psoriasis will cause specific skin lesions, the joints may also become inflamed and painful.
How Do Autoimmune Diseases Develop?
The exact cause s is still unknown, but certain triggers had been found involved in autoimmune reactions.
A virus or drug can alter normal cells, making them appear foreign to the immune system. This results in the immune system attacking these normal cells.
A foreign substance can enter the body and trigger the immune system. With an autoimmune disease, the immune system attacks the wrong organ or cells.
For example, bacteria responsible for strep throat have an antigen that resembles the antigen in heart cells. This can cause complications in people with heart diseases. The immune system will attack the heart as well as the strep throat cells.
The immune system contains B cells, which control antibody production. If they misfunction, they can create abnormal antibodies to attack the body’s tissues. Abnormal T cells play an essential role in autoimmunity too. They help B cells produce autoantibodies by infiltrating tissues and creating inflammation.
The release of a natural substance found in the body can also trigger an autoimmune response. For example, an injury to the eye can cause the fluid found inside the eye to leak into the blood. The immune system may see it as a foreign substance and attack it.
No single test can diagnose an autoimmune disease. Doctors can order tests to find specific autoantibodies produced in certain autoimmune diseases.
Allergies and Autoimmune Disease
In the past, scientists believed that a person who experiences allergic reactions may have a lower risk for autoimmune disease. Based on newer research, this belief no longer exists.
Based on newer research, a person could have both allergies and autoimmune disease responses.
For example, gene BACH2 may play a key role in the development of various allergic and autoimmune diseases. These include MS, asthma, Crohn’s disease, celiac disease, and type 1 diabetes.