Factors That Lead to Atopic Dermatitis
Researchers are still trying to determine the cause or causes of atopic dermatitis. However, some researchers believe that Langerhans cells, which are one type of immune cell in the skin, may be involved. This theory is based upon the following ideas:
- Langerhans cells, located in the epidermis, pick up viruses, bacteria, allergens, and other foreign substances that invade the body.
- Langerhans cells then move to the dermis to deliver the invader to other cells in the immune defense system. These other cells are white blood cells, called T cells, which produce proteins called cytokines. Cytokines attract other cells, such as mast cells, to come to the area and release the chemicals that cause inflammation.
- Langerhans cells are good at activating T cells in the skin of people with atopic dermatitis.
- Langerhans cells in people with atopic dermatitis are thought to be overactive, which can result in a larger-than-normal skin reaction to even tiny amounts of allergens or foreign substances. This causes the redness, itching, and dry skin that are typical of atopic dermatitis.
Other possible explanations for atopic dermatitis include:
- A flaw in a type of white blood cell, called a monocyte, that helps regulate allergic reactions.
- An overproduction of a protein called immunoglobulin E (IgE), which stimulates allergic reactions.
Doctors believe that atopic dermatitis runs in families, but they do not know why some people will get it and others will not. However, doctors do know that certain factors, such as dry weather, cigarette smoke, certain types of foods, and the chemicals in household cleaners, often make the condition worse.