Psoriasis is a skin condition that is often misunderstood; people who have psoriasis can face prejudice and discrimination. The biggest misconception about psoriasis is that it is contagious or that it's "just a skin disease."
Psoriasis is actually an autoimmune disease, which means that a broken immune system sees your skin as an enemy and attacks it relentlessly. As a result, skin cells that would normally take weeks to grow and reach the outer surface of your skin now only take days. This leaves an excess of skin cells on your body, causing the hallmark raised red, white, or silvery patches on your skin.
No one knows exactly why the immune system goes awry. Some cases may be genetic but many are probably a combination of genetic and environmental causes such as stress, infection, medication side effects or even something as seemingly simple as a bug bite. Having a family history of psoriasis, being obese and being a smoker all increase the risk of developing the disease.
Psoriasis is chronic, meaning it stays with you throughout your life. More than 7 million Americans, both men and women, have psoriasis and most develop it between the ages of 15 and 35.
There are five types of psoriasis, the most common being plaque psoriasis. Other forms are guttate, inverse, pustular and erythrodermic, all of which have slightly different symptoms and may appear on the skin of different parts of the body. You can have more than one type of psoriasis at a time.
Psoriasis can affect much more than the skin. About 40% of psoriasis sufferers go on to develop psoriatic arthritis in their joints. Others may develop type 2 diabetes, heart disease and other autoimmune diseases. And like other chronic diseases, psoriasis can lead to depression and damaged self esteem.
We asked experts 11 common questions about psoriasis, from how warm weather and exercise affects your skin, to whether it's safe to get a tattoo.