Easy to say, harder to execute. Here’s the thing: “Stress has an impact on all inflammatory conditions, including psoriasis, because it modifies the immune system,” says Dr. Polla. Stress can induce flares and may contribute to the development of psoriasis in the first place: Psychological stress precedes the onset of disease in 44% of people with psoriasis, studies show, and causes recurrent skin flares in up to 88% of people. Bottom line: Walk in nature, learn yoga, or draw a warm bath. Do what it takes to stay calm.