Which are the causes of Psoriasis?

Psoriasis is a chronic, immune-mediated disease caused by a complex interaction between genetic predisposition, environmental triggers, and a malfunctioning immune system that accelerates skin cell production.

The Pathophysiology of Psoriasis

At its core, psoriasis occurs when the immune system mistakenly signals skin cells to grow and shed too rapidly. In healthy skin, this process takes about a month; in people with psoriasis, it happens in just a few days. This rapid turnover leads to the buildup of cells on the skin's surface, creating the characteristic thick, scaly plaques. Think of it like a faulty "alarm system" in your body that is constantly sounding, causing the skin to overreact by producing new cells at an unsustainable pace.

Genetic and Environmental Factors

While the exact cause remains a subject of intense research, we know that genetics play a significant role. Researchers have identified over 60 locations in the human genome, particularly the HLA-C gene, that increase susceptibility to psoriasis. However, having these genes does not guarantee you will develop the condition. Environmental triggers—such as stress, skin injuries (the Koebner phenomenon), infections like strep throat, or certain medications—often act as the "spark" that activates the immune response in genetically vulnerable individuals.

Distinguishing Causes from Risk Factors

In medical research, we distinguish between the cause (the underlying immune dysregulation) and risk factors (the variables that may trigger an outbreak). While the root etiology of psoriasis is not yet fully understood, current studies are exploring the role of the microbiome and systemic metabolic inflammation. Researchers are investigating how T-cells and cytokines, specifically the IL-23/IL-17 pathway, drive this chronic inflammation, which has led to the development of highly effective biologic therapies.

Medical Disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

References

• National Institutes of Health (NIH) - Genetic and Rare Diseases Information Center (GARD)


• Orphanet: The portal for rare diseases and orphan drugs


• National Psoriasis Foundation (NPF)


• Online Mendelian Inheritance in Man (OMIM)