Psoriasis is an autoimmune disorder caused by overactive T-cells. It makes afflicted areas of skin red and covered with white scales. It's usually most common on the elbows, scalp, knees, and anywhere where there is more skin turnover (when skin cells are dying and being regenerated more than usual).
There are variations on psoriasis, including guttate psoriasis, which is more widespread and appears sort of like random spots of grossness. There's also versions that make your skin appear burned, or even in pus-filled pustules that make psoriasis suck even more.
Poor Psoriasis-afflicted person: Nothing. It's psoriasis.
Passerby: Oh, I'm sorry... Wait... What's psoriasis?
Poor Psoriasis-afflicted person: Like cancer on the outside of your body, only it won't kill you.
It is not contagious. In general, it is a condition that is frequently found on the knees, elbows, scalp, hands, feet or lower back. Many treatments are available to help manage its symptoms. More than 4.5 million adults in the United States have it.
It generally appears as patches of raised red skin covered by a flaky white buildup. In certain kinds of psoriasis, it also has a pimple-ish (pustular psoriasis) or burned (erythrodermic) appearance.
Between 10 percent and 30 percent of people with psoriasis also develop a related form of arthritis, called psoriatic (sore-ee-AA-tic) arthritis.
"No, that's just my psoriasis."