The Blueprint of Skin Health—Genetics, Eczema, and Psoriasis

BY SIDNEY LIN

Our skin is the largest organ of the human body, and its health is of critical importance. Not only does it impact our physical well-being, but it can affect our mental health and self-confidence. Many of the most common skin conditions and diseases can be explained by the underlying role of genetics.

Eczema and Genetics

Eczema is a chronic inflammatory skin condition that causes the skin to become dry, itchy, red, and irritated. It commonly begins in childhood but can occur at any age, and it often follows a relapsing-remitting pattern, with periods of flare-ups followed by times of improvement. People with eczema often have a weakened skin barrier, which makes it harder for the skin to retain moisture and more vulnerable to irritants, allergens, and microbes.

One of the most well-established genetic risk factors for eczema is a mutation in the FLG gene, which plays a critical role in maintaining the skin’s protective barrier. Defects in this gene can lead to increased water loss and greater vulnerability to irritants and allergens. Eczema also has a strong hereditary component. If one parent suffers from eczema or other allergic diseases such as asthma and hay fever, their child has a 50 to 70% risk of developing eczema. If both parents are affected, this risk increases to 80%.

Psoriasis and Genetics

Psoriasis is a chronic skin condition characterized by the rapid overproduction of skin cells. Under normal conditions, skin cells take several weeks to mature and shed, but in individuals with psoriasis, this process occurs within a few days. This leads to a buildup of cells on the skin’s surface, resulting in thick, scaly plaques that are often red, inflamed, and itchy. 

Psoriasis is most strongly associated with the PSORS 1 locus on chromosome 6, specifically the HLA-C06:02 allele. This gene influences the activity of immune cells and inflammatory responses, contributing to the abnormal skin cell proliferation and chronic inflammation characteristic of psoriasis. Psoriasis also has a hereditary component. If one parent has psoriasis, their child has a 15% chance of developing the condition themself. If both parents have psoriasis, that likelihood jumps to 75%. 

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