Psoriasis is a skin disease that causes thick, itchy patches of red skin with silvery scaling.
The top two layers of your skin are called the epidermis and dermis.
New cells at the bottom of the epidermis constantly move up and replace the older cells above them.
Normally, it takes about a month for cells to make this journey.
In psoriasis, cells reach the skin surface in only six to eight days because of a problem with your immune system.
Scientists think your immune system mistakes certain natural substances in your skin as foreign invaders.
This causes your immune system to start a counterattack, called an inflammatory response.
Inflammation is a series of changes that happen in your skin, including: enlarged blood vessels, growth of more blood vessels,
more immune cells in the area, forming groups, and faster creation of new skin cells.
Over time, the process of inflammation becomes a cycle. Damaged skin cells signal more immune cells to come to the area.
In turn, the immune cells cause your skin cells to multiply rapidly, and your skin to get thicker.
This results in raised, itchy, inflamed areas, called plaques, on your skin.
Scientists think that psoriasis is passed down in families through parts of your DNA, called genes.
You can develop psoriasis if you have these genes, then experience certain triggers, such as: skin injuries, dry skin, infections, stress, smoking, and certain medications.
If you have any questions about psoriasis, talk to your healthcare provider.