Is Eczema Hereditary?

Table of contents

Introduction

Eczema which is also referred to as Atopic dermatitis is a chronic, inflammatory skin condition. Hallmarks of eczema include dry, itchy skin with red rashes that may come in flares. It is a common skin disease worldwide. According to research, it may affect up to 30% of children and in some of them, eczema will continue in to adulthood. Although eczema usually appear during infancy and childhood, it can arise in adolescents and adults too, who never had eczema in their childhood.

Eczema is now found to be caused by an interaction of your genes and environmental factors. Most will have a family history, but not everyone with eczema has a genetic link. If you have a sibling or a parent who has eczema, then there is a higher chance for you to develop eczema too. Is this because of the role that genetics play in eczema? Let us find out.

Scientific evidence is strong in supporting the genetic predisposition for development of eczema. Multiple research done worldwide proves that the evidence of gene mutations in several genes may play a role in causing eczema. In this article we will further discuss how eczema becomes hereditary and the research evidence for the relationship between eczema and genetics.

Does research, point towards a relationship between your genetics and eczema?

Birth cohort studies are ideal to assess the health outcome from birth in to childhood with regards to eczema. Given the age specific emergence of eczema, it provides that eczema can be in fact hereditary.

Research data indicates that several genes may be associated in developing eczema. A research review done in 2010 analyzed the whole human genome. Several genes were found to significantly alter the function and composition of skin in patients with eczema. There is an allergic or an inflammatory response in eczema. Some genes affect the immune system leading to this inflammatory response. The other genes will impact specifically on the eczematous skin.

Genes coding for the function of our skin

Our skin has 3 layers – the epidermis, dermis and hypodermis. Epidermis is the outermost layer which is responsible in maintaining the barrier function of our skin. If your skin barrier is healthy, it will support retention of moisture as well as protecting your body from foreign substances that can harm us, such as allergens, bacteria and toxins.

A gene called the FLG gene, instructs the skin cells to make a large protein named ‘Filaggrin’ in the epidermis. Filaggrin plays an important role in barrier function of our skin. It connects the structural proteins in the outermost skin cells and form tight bundles. Filaggrin strengthens the skin cells and create a strong barrier for protection. Research shows that the FLG gene has a mutation in the DNA sequence in about 50% of patients with eczema. Therefore, specific instructions are not given by this defective gene to cells to make filaggrin. Filaggrin is not produced properly when the message is defective. Less Filaggrin will make your skin barrier weak. Epidermis will become dry and unhealthy which will be prone to allergic reactions and infections. When the filaggrin forming gene is mutated and defective, the protective barrier function is lost. This will make you prone for eczema.

When there are anomalies in the FLG gene, these people will also be prone to develop asthma and hay fever. This is a classic triad. It is known as atopy. The classic triad of atopy includes eczema, asthma and allergies like hay fever and allergic conjunctivitis. Atopy refers to this genetic tendency to develop allergic diseases and they run in families. These families are known as atopic families. Atopy is typically associated with heightened immune response to many common allergens such as inhaled allergens and food allergens.

In another study, a gene called SPINK5 is also found to be mutated in patients with eczema. This gene is known to instruct skin cells to make proteins. How this mutation in the SPINK5 gene affects to develop eczema is still not clear.

Genes coding for the function of our immune system

The genes that are associated with our immune system include genes forming IL (interleukin) 4, 5 and 13. These genes are found to promote allergy and inflammation. They can cause a reduction in the immune response towards pathogens as well as affecting the skin barrier function.

Interleukin 33 is an inflammatory cytokine that is over expressed in the skin cells of patients with eczema. IL 33 gene stimulates many cells to produce cytokines and create inflammation. It is mainly associated with the itch – scratch cycle of eczema.

Can Eczema be a feature of a separate genetic disorder?

Eczema can be associated with some genetic disorders that have many signs and symptoms including skin abnormalities and immunodeficiency. Examples of such disorders include;

Immune dysregulation, X- linked (IPEX) syndrome, Netherton syndrome, Poly-endocrinopathy, Enteropathy, severe dermatitis, metabolic wasting syndrome (SAM) and multiple allergies.

Are genetics the only reason to get eczema?

Although genetics increases your risk of developing eczema, this is not the only cause. There are many causes that are associated with developing eczema. Usually it is a combination of several causes and risk factors. As mentioned earlier, both genetics and environmental factors play a role in developing eczema.

Here are some of the identified causes and risk factors of eczema;

  • Exposure to cigarette smoke during infancy – smoking indoors and maternal cigarette smoking
  • If the mother went through high levels of psychological stress during the pregnancy, the offspring can be affected
  • If your immune system is defective or over reactive
  • If your skin is very dry and unhealthy
  • Dysfunction of the skin barrier – dysregulation of the immune system may be a cause
  • Certain endocrine disorders like thyroid dysfunction

Now that we know that eczema has a genetic tendency, we will learn more on how an eczema flare occurs.

An eczema flare up is triggered by environmental factors. Once our skin is already at risk to develop eczema because of our genes, many factors can act as triggers to develop a flare.

Environmental triggers for eczema flare-ups include;

  • Irritants such as soap, detergents, cosmetics, perfume, cleaning products, formaldehyde – irritants are found in everyday products we use. One chemical which may act as an irritant to a particular individual to trigger an eczema flare may not be so for another person.
  • Cold air
  • Hot weather and heat
  • Cigarette smoke
  • Airborne allergens
  • Out- door pollutants
  • Fabrics like polyester, wool
  • Certain metals like nickel

You may be having eczema because of your genes, or you still may not have developed any symptoms although you have a strong family history. Naturally you will be worried because of this hereditary tendency, whether you will be a victim of eczema. But if we are careful and we look after our skin well, we should be able to delay onset of eczema or prevent a flare up.

What can we do to prevent an eczema flare up, even if we are genetically prone?

  • Moisturize and hydrate your skin well
  • Use a humidifier at home when using heaters during winter to prevent dehydration of your skin
  • Manage your stress well by practicing relaxation techniques such as yoga and meditation
  • Identify and avoid irritants which can trigger a flare such as wool, certain chemicals and other irritants
  • Avoid using harsh soaps and detergents

Conclusion

Eczema can affect up to 30% of children worldwide. It often afflicts infants in the 1st few months of life. This can be the first indicator of this atopic tendency. Research indicates that eczema or atopic dermatitis has a strong genetic link. Several genes that affect our immune system and skin function may play a role while environmental factors and stress can trigger eczema. There are many things you can practice to prevent getting a flare. However, once you are genetically prone towards eczema, you may get a flare at some time in your life. Do not get disheartened. Seek treatment early. Although there is no cure for eczema you can successfully manage flares and keep your condition under check, if you stick to your treatment plan and follow up regularly with your dermatologist.

 

 

 

References:

https://medlineplus.gov/genetics/condition/atopic-dermatitis/

https://www.aaaai.org/Tools-for-the-Public/Allergy,-Asthma-Immunology-Glossary/Atopy-Defined

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2957505/

https://pubmed.ncbi.nlm.nih.gov/31455506/#:~:text=Interleukin%2D33%20(IL%2D33,for%20the%20development%20of%20AD.