What is psoriasis?

With psoriasis, your immune system attacks your own body. This causes inflammation of the skin. The skin cells divide more rapidly because of the psoriasis. These extra skin cells form red, scaly patches (photo). These patches can be itchy and sometimes painful.


Photo: mild psoriasis patches
on the elbow.


Photo: severe psoriasis patches
on the ankle.

The patches can occur anywhere on the body, but most often on:

  • the outer elbows and knees;
  • the lower legs;
  • the tailbone
  • the scalp.


Figure: where do psoriasis patches occur?

When people think of psoriasis they most often associate it with the skin. However, it may also occur in the nails and joints.

Psoriasis is more common within a family.

Psoriasis can be local or very widespread. The disease can naturally improve, worsen or remain the same. Sunlight usually improves your psoriasis. Stress, other inflammations and certain medications can make it worse. If you get a wound somewhere, a new psoriasis patch may occur there.