濕疹如何影響免疫系統?

How eczema affects the immune system

According to the National Eczema Association, people with eczema have an immune system that overreacts to substances inside or outside their body. The immune system responds by producing inflammation (called an inflammatory response), causing symptoms including:

  • itching
  • pain
  • Depending on the person's skin tone, patches of skin can turn red, dark brown, purple or gray
  • ooze
  • rash

Further research confirms that the immune system is a cause of eczema. Allergens or irritants can cause overstimulation of the body's immune system. This reaction manifests itself on the skin as inflammation or inflammation of the skin.

Some connections between the two are discussed below:

Eczema causes cell imbalance

The immune system has many roles to protect people from infections, allergens, cancer, and more. White blood cells called helper T lymphocytes (Th) are important for adaptive immunity, in which the immune system learns to protect itself from foreign invaders such as bacteria. The two main types of T lymphocytes are Th1 and Th2 cells.

In people with eczema, these two cell types are not balanced and there are more Th2 cells, which can lead to more inflammation and the following conditions:

  • Moisture loss from the skin barrier
  • Allergens (such as pollen or dust mites) enter the skin
  • Irritants (such as soap or detergent) enter the skin

A 2019 study confirmed that eczema occurs due to tissue infiltration of Th2 cells and other cells produced by the immune system, leading to a compromised skin barrier and underlying inflammation.

Eczema can lead to skin infection

People with eczema have increased skin colonization, which means there are more bacteria on the skin. This can make a person more susceptible to skin infections, especially if not treated promptly.

People with eczema are more colonized with Staphylococcus aureus, which makes them more susceptible to impetigo. Impetigo is an itchy, painful skin infection.

Stress can make eczema worse

Stress may trigger eczema flare-ups and affect the immune system's response.

Specifically, elevated cortisol levels caused by stress and anxiety can suppress the body's immune system and trigger inflammatory reactions such as eczema.

Does having eczema mean you have a weak immune system?

Eczema and the immune system have a complex relationship. Having eczema does not mean a person has a weak immune system.

However, eczema may be a sign that a person's immune system is sensitive or overreactive to certain irritants, and therefore may be dysregulated rather than weak.

As part of the immune response, the body produces white blood cells and other substances to attack irritants that invade the skin, causing inflammation or symptoms. The fact that a person's immune system reacts in this way indicates that it is not weak.

Still, in some cases, eczema can be caused by a disease that affects the immune system.

Immunodeficiency

In rare cases, eczema may also be due to an underlying inherited immune deficiency, such as autosomal dominant hyper-IgE syndrome (AD-HIES). In this disease, inflammation, a flaky rash (eczema), and skin infections appear at birth or in early infancy.

Is eczema an autoimmune disease?

The National Eczema Association defines autoimmune diseases as conditions in which the immune system attacks the body's own healthy tissues.

While an overactive or dysregulated immune system can contribute to the development of eczema, it does not cause the body to attack skin cells. Instead, allergens or irritants enter the skin barrier and cause eczema symptoms.

Although eczema and autoimmune diseases are similar, eczema is not technically an autoimmune disease.

generalize

People with eczema often have an overreactive or sensitized immune system to allergens or irritants. The immune system responds by producing inflammation (an inflammatory response), which causes eczema symptoms. People with eczema often have an overactive immune system rather than a weak immune system.

Still, people with eczema are at increased risk for skin infections due to a compromised skin barrier. People with eczema tend to have greater colonization with Staphylococcus aureus, making them more susceptible to bacterial infections such as impetigo.

Although eczema and autoimmune diseases are similar, eczema is not technically an autoimmune disease.

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