Causes of Psoriasis

The exact cause of psoriasis isn’t fully understood, but scientists believe psoriasis is the result of several factors, including genetics, environmental factors, and the immune system.

The Genetic Link

If you have psoriasis, it’s possible that someone in your family may have had it too. That’s because there appears to be a genetic link for psoriasis.

One out of 3 people with psoriasis reports having a relative with the disease. And researchers say that up to 10% of the general population may inherit one or more genes that predispose them to psoriasis, though only 2% to 3% of people with the gene actually develop the disease.

Environmental Triggers

Certain environmental factors may trigger the psoriasis genes, causing the disease to become active. These environmental triggers vary from person to person, and what causes psoriasis to develop in one person may have no effect on someone else.

Some triggers known to impact psoriasis symptoms include:

  • Stress

  • Injury to skin (cuts, scrapes, bug bites, severe sunburns)

  • Infection (such as strep throat or thrush)

  • Certain medications (including lithium, antimalarials, quinidine, indomethacin)

The Key Role of the Immune System

Your immune system is meant to protect you when an “intruder,” like a cold virus, enters your body. But sometimes the immune system mistakes your body’s heathy cells for intruders and attacks them. While the exact cause of psoriasis isn’t fully understood, scientists believe psoriasis is the result of several factors, including the immune system.

When you have psoriasis, your immune system is overactive. This creates inflammation inside the body, which is a cause of the symptoms you see on the skin. More healthy cells are produced than normal. Those excess cells get pushed to the surface of your skin too quickly. Normally, it takes about a month for your skin cells to cycle through your body. With psoriasis, it takes days.

Your body simply can’t shed skin cells that quickly, so the cells build up on the surface of your skin. The thick, red patches you see on your skin (called plaques) are actually a buildup of excess skin cells.

Psoriasis and Comorbidities

When a person has two or more diseases at one time, these are called “comorbidities.”

Comorbidities associated with psoriasis include other immune conditions such as psoriatic arthritis and Crohn’s disease.

It’s important to keep your doctor informed about any symptoms you may be having so the two of you can decide how to possibly avoid or manage comorbidities.

Other Comorbidities

Psoriasis has been linked to other health conditions. Psoriasis is not thought to cause these conditions or vice versa. Patients with psoriasis have a greater likelihood of being diagnosed with the following conditions:

  • Psoriatic Arthritis

  • Type 2 diabetes

  • Cardiovascular disease

  • High blood pressure

  • Crohn's Disease

  • High cholesterol

  • Depression

  • Ulcerative colitis

Talk to your doctor if you have any of these health conditions along with signs and symptoms of psoriasis. It’s important to tell your doctor about other symptoms, because each medical condition needs to be treated separately and may require different medication.

Myths and Misconceptions

Because psoriasis is often misunderstood, there are many myths and misconceptions about what psoriasis is and how people get it. A doctor discusses the importance of helping others understand the disease.

Dr. Menter is chairman of the Division of Dermatology at a prominent U.S. academic medical center. Dr. Menter is also a paid consultant of AbbVie.

Psoriasis Is NOT Contagious

One of the greatest misconceptions about psoriasis is that one person can “catch it” from another. That is absolutely a myth!

Psoriasis is a disease of the immune system, and is not something you can catch. It’s good to know the facts about psoriasis and to be prepared for the questions you’ll get from others.

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