Psoriasis can develop pretty much any where on your body.
Everybody’s skin gets dry and a little flaky once in a while, and usually, it’s easy to clear up—all it takes is applying lotion more frequently, switching soaps or laundry detergents, or avoiding common skin allergens like nickel and certain preservatives. But what if you’ve developed itchy, painful, rough patches of skin that just won’t go away? You might have psoriasis. Learn more about what causes psoriasis, what it looks and feels like, how it’s diagnosed, and your treatment options.
What is psoriasis?
Psoriasis is a chronic autoimmune disease that causes a buildup of skin cells. This buildup causes rough patches that are often scaly, red, and inflamed. Psoriasis can affect any part of the body, but it most commonly develops behind the elbows and knees, as well as the scalp, back, face, palms, and feet.
Psoriasis affects roughly 7.5 million people in the United States, according to the American Academy of Dermatology. It can strike at any time in your life, but tends to first develop between the ages of 15 and 30 or between the ages of 50 and 60. Most people have mild-to-moderate psoriasis, but 20 percent of people have moderate-to-severe psoriasis, meaning it covers more than 5 percent of the body’s surface.
Psoriasis can occur in men and women and in people of all races. There are several types of psoriasis, but the most common type—which affects 80 to 90 percent of psoriasis patients—is called plaque psoriasis.
Let’s bust one common myth right now: Psoriasis is not contagious. So if your rash accidentally rubs on someone else or another person touches it, you don’t have to worry about spreading it. But the rash can be unpleasant to look at and can be embarrassing if it’s on a body part that’s regularly exposed to the public.
What causes psoriasis?
To be frank, we just don’t know yet what, exactly, causes psoriasis. Here’s what we do know: White blood cells in your body called T cells, which you can think of as part of your body’s department of defense, mistakenly think that your body is under attack. So they start to produce proteins that promote inflammation.
“Because of this pro-inflammatory cascade, the skin cells (keratinocytes) then respond by reproducing. But the old skin can’t shed fast enough. So it gets heaped up and forms plaques,” says Bobby Buka, MD, a dermatologist at Bobby Buka MD Dermatology in New York City. “Normally, in someone without psoriasis, the epidermis (the outer layer of skin) will turn over every 28 days. In a psoriatic patient, that turnover happens every seven days.”
|Read on: Psoriasis 101 – Symptoms, Causes, Treatments, & Pictures|