Are your skin problems caused by psoriasis?

More than 7 million American adults have psoriasis, a chronic skin disease caused by a glitch in the immune system. It’s a widespread and potentially serious condition linked with problems

ranging from depression to heart disease. And yet psoriasis is often initially mistaken for something else, experts say. Psoriasis, in its most common form, produces inflamed scaly patches.

The issue is, “there are many other diseases that produce red scaling patches,” says Robert Kalb, M.D., a clinical professor of dermatology at the State University of New York at Buffalo

Jacob School of Medicine and Biomedical Sciences. Most notably, eczema, an even more common skin disorder, causes scaly, inflamed skin. And familiar fungal infections of the skin, including

ringworm and athlete’s foot, also create scaly patches. Some rarer conditions cause symptoms that might look like psoriasis as well. Dermatologists and other doctors well trained in skin

diseases usually can diagnose psoriasis quickly by examining your skin and asking a few questions about your medical history, Kalb says. Occasionally, doctors might need to scrape off or cut

out a very small skin sample to get a clear answer, says Mark Lebwohl, M.D., chairman of the Department of Dermatology at Icahn School of Medicine at Mount Sinai in New York. If you

haven’t seen a doctor yet, here are nine clues that the scaly patches on your skin might be psoriasis: 1. THE PATCHES HAVE CLEAR BORDERS Psoriasis patches, unlike patches of eczema, have

“sharply demarcated” edges that you can clearly see and feel, Lebwohl says. The patches usually look red but might appear purple in dark-skinned people, he adds. A ringworm patch also might

have well-defined edges, but it has a distinct circular shape and often a clear area in the center of the ring, according to Cleveland Clinic. If there’s any doubt about whether you have

psoriasis or a fungal infection, a doctor can scrape off a bit of the affected skin and look at it under a microscope, Lebwohl says. 2. THE INFLAMED SKIN IS COVERED BY THICK SCALES In plaque

psoriasis, the most common form, an overactive immune system causes skin cells to reproduce too rapidly and build up on the skin surface in thick scales, or plaques. The scales may be white

or silvery. Eczema patches typically are covered with finer, flakier scales of dry skin. 3. THE PATCHES ARE ON YOUR ELBOWS, KNEES, SCALP, LOWER BACK OR ALL OF THE ABOVE While psoriasis can

show up anywhere on your body, the bony parts of the knees and elbows, along with the scalp and lower back, are especially common. Eczema, by contrast, often appears in the creases of elbows

and knees and other skin folds, especially in children. It can also show up on the face or hands of adults, according to the National Eczema Association. Most people with psoriasis have it

in more than one place, Kalb says, so if you have one suspicious spot, your doctor should check your whole body.