Is Eczema Genetic? Hereditary Factors Explained

If you have eczema or your child does, you might wonder whether genetics plays a role. The short answer is yes—research shows that eczema has a strong hereditary component. Studies estimate that about 75% of eczema risk comes from inherited genetic factors, making family history one of the most significant risk factors for developing this chronic skin condition.

Understanding the Genetic Link

Eczema, also called atopic dermatitis, often runs in families. Twin studies provide strong evidence of this genetic connection. Identical twins show a 72-86% chance of both having eczema, while non-identical twins show only a 21-23% chance. This difference highlights how important genes are in determining who develops the condition.

The most significant genetic factor involves mutations in the filaggrin gene (FLG). This gene makes a protein that helps form your skin's protective barrier. When this gene has mutations, your skin can't hold moisture well and becomes more vulnerable to irritants and allergens. About 20-30% of people with eczema have these filaggrin mutations, compared to only 8-10% of people without eczema.

Family History and Risk

If eczema runs in your family, your child's risk increases significantly. Here's what the research shows:

• If one parent has eczema: 60% chance the child will develop it

• If both parents have eczema: Nearly 80% chance

• If you have a family history of asthma or hay fever: 2-3 times higher risk

About 40% of people newly diagnosed with eczema report at least one close family member with the condition. The connection between eczema and other allergic conditions like asthma and hay fever is so strong that doctors refer to it as the "atopic march."

How Genes Affect Your Skin Barrier

The filaggrin protein acts like a building material for your skin's outer layer. It binds structural proteins together to create a tight, protective barrier. When working properly, this barrier keeps moisture in and irritants out.

When filaggrin mutations occur, the barrier becomes weak and leaky. Your skin loses water more easily and allows allergens, bacteria, and irritants to penetrate. This triggers inflammation and the characteristic itchy, dry patches of eczema.

Besides filaggrin, other genes involved in immune function also play a role. Genes that control T-cells and proteins called cytokines can make your immune system overreact to substances that wouldn't bother most people.

Genetics Aren't Everything

While genetics plays a major role, it's not the whole story. Environmental factors also matter. You might carry eczema genes but never develop symptoms, or you might develop eczema without a strong family history.

Environmental triggers that can activate genetic predisposition include:

• Dry air and cold weather

• Harsh soaps and detergents

• Allergens like dust mites and pollen

• Stress and hormonal changes

Understanding the genetic component helps explain why some people struggle more with eczema than others. Even with a genetic predisposition, proper skincare and avoiding triggers can help manage symptoms effectively.

When to See a Dermatologist

If you or your child has persistent itchy, dry, or inflamed skin, especially with a family history of eczema or allergies, consult a dermatologist. They can confirm the diagnosis and create a personalized treatment plan. Early intervention is particularly important for children, as proper management can reduce the severity of symptoms and may lower the risk of developing other allergic conditions.