Eczema refers to a group of conditions that result in skin irritation and inflammation. While researchers are unsure of the exact cause of eczema, evidence suggests that changes in genes, problems with the immune system, and exposure to environmental triggers all contribute to the development of eczema.

Research indicates that eczema affects roughly 1 in 5 children and about 1 in 50 adults. Eczema normally refers to atopic dermatitis, which is a chronic skin condition. It causes inflammation, resulting in dry and itchy skin. The skin may also weep clear fluid when scratched.

Genetic and environmental factors may have a role in the development of eczema. While anyone can develop eczema, research suggests that people with allergies, asthma, and eczema themselves are more likely to have children that develop eczema.

In this article, we will explore whether eczema is hereditary, which genes it involves, and how eczema occurs.

A parent and their children, who may inherit eczema.Share on Pinterest
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Anyone can develop eczema. However, if eczema runs in a person’s family, then their likelihood of also developing eczema increases. A 2015 study found that the chance of inheriting atopic eczema is approximately 75%.

Genes carry the genetic information that contains instructions to make proteins. Every person will have two copies of each gene, one from each parent. A person may inherit mutated genes from one or both of their parents that increases their chance of developing eczema.

While researchers do not fully understand the genetics of eczema, evidence suggests that several genes may contribute to the development of the condition, and, in rarer cases, a single inherited gene mutation may lead to eczema.

One such gene is CARD11, which carries the information to make a protein that is necessary for the proper functioning of lymphocytes. Lymphocytes are immune cells that protect the body from infections.

Mutations in the CARD11 gene can result in atopic eczema due to a weakened immune system. Researchers have identified at least five CARD11 mutations that may be present in people with atopic eczema. A 2017 study found that a mutation in one copy out of the two inherited CARD11 genes was enough to cause atopic eczema.

Another gene that plays a role in the development of eczema is KIF3A, which codes for a protein involved in protein transport and cell signaling. A 2020 study found that genetic variation in KIF3A may increase the risk of developing atopic eczema. This is due to the skin barrier becoming weakened and water loss from the skin.

Another gene that may contribute to the development of eczema is FLG. This gene codes for profilaggrin, which produces the protein filaggrin. This protein plays a role in the maintenance of the skin barrier and skin hydration.

There is a strong association between mutations in the FLG gene and the development of atopic eczema. Between 20–30% of people with atopic eczema have an FLG gene mutation. Researchers have identified 40 FLG mutations in people with atopic eczema. Atopic eczema is usually more severe in people who have mutations in both copies of the FLG gene.

Eczema affects an estimated 30% of the United States population. Eczema normally manifests before the age of 5 in 70% of cases. It is currently unknown what exactly causes eczema. However, researchers believe that a combination of genes and environmental triggers is responsible.

A person may inherit mutated genes from their parent or they may acquire a gene mutation throughout their lifetime. A person may have a gene that increases their likelihood for eczema, but that gene may not be active until they become exposed to an environmental factor.

Other factors and triggers can also cause the development of eczema. A person may have eczema that results from an allergy or irritation to certain substances. This is known as contact dermatitis.

Contact dermatitis results in the skin being itchy. a person may also develop a rash and blisters. Common triggers of contact dermatitis include:

  • nickel
  • fragrances
  • latex
  • urushiol found in poison ivy, poison, and poison sumac
  • disinfectants
  • pesticides
  • detergents
  • soaps
  • plants

Environmental and biological factors can also cause eczema. For example, stress or smoking tobacco are among the things that can cause a type of eczema called dyshidrotic eczema.

Other factors that may increase the risk for atopic eczema include:

  • air pollutants
  • water hardness
  • tobacco smoke exposure
  • diet
  • alcohol consumption
  • living in urban settings

Click here to learn more about the different types of eczema.

Eczema is not contagious. This means that a person cannot acquire eczema from being in contact with someone who has the condition.

However, due to the cracking of the skin that eczema causes, a person with eczema can be more vulnerable to infections. Skin infections are common in people with eczema and these infections can be contagious.

For example, people with atopic eczema are at a higher risk of developing eczema herpeticum. This is an infection caused by the herpes simplex 1 (HSV-1) virus. It results in blisters on the skin which may weep or bleed. Eczema herpeticum is contagious.

Click here to learn more about eczema herpeticum.

Eczema is a chronic skin condition that results in skin irritation and inflammation. While scientists are still learning more about the condition, evidence suggests there is a genetic predisposition and that eczema may be hereditary. Researchers have identified that mutations in KIF3A, FLG, and CARD11 genes are commonly associated with the development of eczema.

Other factors can also cause eczema. For example, environmental triggers such as pollution and tobacco smoke and biological factors such as stress can also result in eczema. Eczema is not contagious. However, a person with atopic eczema may be at a higher risk of developing skin infections. These skin infections may be contagious, such as eczema herpeticum.