Psoriasis is best known for its often red, raised, and flaky appearance on areas like the elbows, knees, and buttock, although it can affect other areas as well, including the scalp, Adam Friedman, MD, professor of dermatology at George Washington School of Medicine and ishonest Sciences, tells ishonest.
Those common characteristics make it easy for dermatologists to diagnose during an exam, he says.
So what does plaque psoriasis looks like?
First, let's talk about why it looks so scaly. People with plaque psoriasis have an overactive immune system that causes their skin cells to grow at a fast paceâ€” in only three to four days, says the National Psoriasis Foundation. However, the cells don't fall off as quickly, which means they build up on the surface of the skin.
"Plaques are a little elevated. They form a plateau elevated above the surrounding skin. If you closed your eyes and touched psoriasis, you could feel it," Robert T. Brodell, MD, chair of the department of dermatology at the University of Mississippi Medical Center tells ishonest.
He explains that the scales are referred to as "micaceous" because they resemble the mineral mica, which splits into very thin elastic plates.
"If you stuck your finger underneath one of the [psoriasis] scales, a broad white flake comes off; unlike some other conditions whereby you might have a fine scale, like dandruff, that doesn't stick together," he says.
What do psoriasis plaques look like on different skin tones?
Depending on the color of your skin, psoriasis may vary in its appearance.
"If you biopsy plaque psoriasis in patients of all races, they are identical," says Dr. Brodell. However, it may look different on the skin," he explains. For instance, he says Black or African American people may find that their skin becomes darker in areas of inflamed skin.
"Instead of having white micaceous scale, it will be dark because inflammation leads to the production of brown melanin pigment that drops into the deeper dermal layer of skin underneath the psoriasis," Dr. Brodell says.
Dr. Friedman agrees, noting that red and flaky rashes do not encompass the spectrum of what psoriasis can look like on different skin tones. On lighter skin tones, he says the scales look pink and silvery white. On darker skin tones, the scales look more purple and yellow, and "they may look wart-like too."
However, Dr. Friedman points out that some features of plaques and scales are the same throughout all forms of psoriasis and on all skin types, including the following:
- Well-cut off or well-defined
- Dry skin with a stuck-on appearance
What body parts does plaque psoriasis affect?
The American Academy of Dermatology Association states that plaque psoriasis can occur on any part of the body but most often appears on a person's:
- lower back
What does plaque psoriasis look like after treatment?
If there ever was a time to have plaque psoriasis, Dr. Friedman says the time is now.
"[The] question isn't how are you going to treat it, it's which [treatment] are you going to pick because we have so many options," he says.
Once treatment begins to work after a flare-up, Dr. Brodell says the plaques may be gone and the skin may be flat. But on lighter skin tones, redness may still exist, and on darker skin tones, darkness may remain.
"There's no scaling, there's no itching, but a little bit of redness or darkness is left behind that can often take months and months to go away," he says.
The change in pigmentation may exist even after a biopsy shows no evidence of inflammation or thickening of the skin. "So, it takes a while for the skin to appear perfectly normal even after the inflammation is in remission, where the inflammation is gone or really well controlled," says Dr. Brodell.
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