Over time, the understanding of psoriasis has changed a lot. Psoriasis used to be thought of as just a skin condition. But now it's known to be a lifelong condition of the immune system. Learning about the role of the immune system can help you better understand how psoriasis works and what treatment options are available.

How does your immune system work?

One of the many ways your immune system protects your body against infection and diseases is through inflammation. In other words, it sends blood and immune cells to injured or threatened parts of the body to help stop infections. For example, when you scrape your knee, your skin may swell and turn red. That’s your immune system working to heal the injury. This is known as an inflammatory response.

What does your immune system have to do with psoriasis?

Plaque psoriasis is the most common form of psoriasis. When you have psoriasis, your immune system does not work properly. It can make too much of several proteins. Some of these proteins can make skin cells grow too quickly. Normally, skin cells grow, mature, and shed off the skin over the course of a month. However, in people with plaque psoriasis, one of the most common forms of psoriasis, that process takes just 3 to 4 days. The body can’t shed the skin cells quickly enough, so they build up on the surface of your skin and form into raised, red patches, known as plaques. Sometimes these plaques have silvery scales.

Are there treatments that work on the immune system?

There are many treatment options available and they work in very different ways. Some treatment options include topical medicines, phototherapy, and systemic therapies. Systemic therapies and some topical treatments for psoriasis work on the immune system.