to appear on the skin. There are multiple types of psoriasis, including plaque, guttate, inverse, pustular and erythrodermic. Plaque psoriasis is the most common form of psoriasis. Approximately 1.5 million Americans suffer from moderate to severe plaque psoriasis.
Plaque psoriasis is a disease of the immune system. While plaque psoriasis may look like just a skin condition, it is in fact a disease of the immune system. The immune system protects the body from infections and diseases. In patients with plaque psoriasis, certain immune cells are activated and play an important role. They overproduce inflammatory proteins such astumor necrosis factor (TNF). These proteins can cause skin cells to grow too quickly. The skin cells build up and form raised, red patches often with a silvery scale, known as plaques. These plaques
may itch, be painful, and can bleed. Knowing how plaque psoriasis develops—from inside the body—can help you understand how some treatments can help.
Symptoms of plaque psoriasis
Plaque psoriasis causes raised red patches with a silvery scale to appear on the skin. They can appear anywhere on the body, but are most commonly found on the elbows, knees, scalp, and lower back. People with plaque psoriasis may notice that there are times when their skin worsens, then gets better. Factors
that cause these "flare-ups" can include:
- emotional stress
- injury to the skin
- some types of infections
- reactions to certain drugs