Eczema develops when a person’s immune system becomes sensitized to proteins from a source inside or outside the body. The immune system becomes overreactive and sets off inflammatory processes that attack the skin.
Most scientists believe eczema is probably caused by a combination of inherited and environmental factors. Still, no one has identified why some people develop eczema and some people don’t.
Risk factors for eczema
It is important to note that while science is good at finding correlations, or apparent relationships, between factors and disease, correlation does not prove that the factor causes the disease. Many risk factors for eczema have been identified and are being studied, but none have been pinpointed as the cause of eczema.
Age is a factor in the development of eczema. Younger children are more at risk for developing eczema than are older people.
People are more likely to develop eczema if a close relative also has eczema. People with eczema are also more likely to develop other immune-related conditions including asthma and food allergies. These three related conditions – allergies, eczema, and asthma, known as the “atopic triad” or “atopic march” – tend to run in families. Approximately 70 percent of those diagnosed with atopic dermatitis have a family history of atopic conditions.
One gene that has been identified as a significant influence in the development of eczema is the gene that controls the production of filaggrin. Filaggrin is a protein that helps form a protective barrier on the outer layer of skin. Studies have shown that those with the genetic variant resulting in lower levels of filaggrin are more likely to develop eczema.
Approximately 35 percent of people with food allergies also have eczema. Genes that influence skin absorbency may contribute to eczema. A new theory about the development of food allergies suggests that the immune system becomes sensitized to foods when babies receive early exposure to the foods via their skin. If babies with vulnerable skin are kissed and touched by people with food on their hands or mouths, the theory suggests, perhaps the proteins absorb into the baby’s skin, and the immune system interprets the food proteins as dangerous invaders.
Children born to older mothers appear to be more likely to develop eczema.
Living in developed countries and urban areas seems to increase the risk for developing eczema.
Those who live in colder, drier climates appear to be more likely to develop eczema.
Can eczema be prevented?
Since scientists are not yet sure why some people develop eczema, there is no way to prevent it. Hereditary factors that seem to raise the risk for eczema are beyond anyone’s control.
Factors that may reduce the risk for developing eczema include:
Can stress cause eczema?
Stress is not believed to cause eczema. However, the chemicals the body produces in response to stress can also worsen symptoms of eczema. Stress is a trigger for eczema flares in some people.