An estimated 8 million Americans live with psoriasis, a chronic autoimmune disease characterized by raised, discolored plaques of skin covered with scales, according to the National Psoriasis Foundation. While typically appearing on elbows, knees, and the scalp, the condition can affect any part of the body and ranges in severity.
Psoriasis occurs when the immune system mistakenly attacks healthy skin cells, leading to inflammation and rapid skin cell production. The resulting plaques can be itchy, sore, and even bleed. Skin discoloration varies based on skin tone. appearing as red with silver scale on fairer skin and purple with gray scale on darker skin. Symptoms also include dry, cracked skin, pitted or thickened nails, and cyclical rashes that flare and subside.
The disease has a strong genetic component, affecting approximately 2 percent of the U.S. Population, but scientists have identified that genes alone don’t determine risk. “It’s likely that multiple genes need to be affected to allow psoriasis to occur and that it’s frequently triggered by an external event, such as an infection,” explains James W. Swan, MD, a dermatologist specializing in psoriasis in Maywood, Illinois.
Several factors can trigger or worsen psoriasis flare-ups. Stress is a significant contributor, with symptoms often escalating during periods of high stress and improving with relaxation techniques like exercise, yoga, and meditation, according to Vesna Petronic-Rosic, MD, a visiting professor at the University of Illinois Chicago. Cold, dry weather exacerbates symptoms by stripping moisture from the skin, though some individuals find sunlight beneficial due to the anti-inflammatory effects of UVB rays. However, doctors caution that controlled phototherapy is more effective and safer than sun exposure.
Other triggers include vaccinations, which can cause a flare due to skin puncturing, and certain medications like beta-blockers and lithium. Upper respiratory infections, particularly strep throat, can also activate the immune system and provoke outbreaks. Smoking is linked to an almost doubled risk of developing psoriasis, and heavy smokers are more than twice as likely to experience the condition compared to non-smokers.
Dietary factors may also play a role. While nutritional supplements haven’t shown consistent benefits, some individuals find relief by avoiding certain foods or adopting a gluten-free diet, particularly if they have celiac disease. Reducing intake of nightshade vegetables—eggplant, tomatoes, white potatoes, and peppers—may also help. Alcohol consumption can contribute to inflammation and dehydration, potentially worsening psoriasis symptoms.
There are several types of psoriasis, including plaque psoriasis, the most common form; guttate psoriasis, often linked to strep infections; inverse psoriasis, affecting skin folds; pustular psoriasis, characterized by pus-filled blisters; and erythrodermic psoriasis, a rare and severe form causing widespread redness and exfoliation. Nail psoriasis can cause pitting, discoloration, and nail separation.
Diagnosis typically involves a physical examination by a dermatologist, potentially supplemented by a skin sample analysis. While there is currently no cure for psoriasis, various treatments can manage symptoms. Topical treatments, including prescription steroids and newer nonsteroidal creams like roflumilast and tapinarof, are used for mild to moderate cases. Biologic drugs, which alter the immune system, are administered via injection or tablet. Other options include apremilast, oral retinoids, methotrexate, cyclosporine, and light therapy.
While psoriasis cannot be prevented, maintaining moisturized skin, avoiding triggers, limiting alcohol intake, and adopting a healthy lifestyle can help reduce flare-ups. Individuals with psoriasis are at increased risk for other health conditions, including heart disease, diabetes, obesity, high blood pressure, and uveitis. Up to 30 percent of psoriasis patients may also develop psoriatic arthritis, an autoimmune disease affecting the joints. The risk of these complications is greater for those diagnosed at a younger age or with more severe psoriasis.
Psoriasis affects different racial and ethnic groups differently. We see less common in Black, Indigenous, and People of Color (BIPOC) populations, but may be more severe. Psoriasis can present differently on skin of color, appearing violet with gray scale in Black Americans, and salmon-colored with silvery-white scale in Hispanic individuals. BIPOC individuals are also less likely to receive timely and appropriate treatment, potentially due to systemic racism and disparities in healthcare access. Dermatology textbooks have historically included limited images of skin of color, hindering accurate diagnosis and treatment.
