Researchers have uncovered the key drivers of psoriasis, a chronic autoimmune skin disease that eventually leads to psoriatic arthritis and other autoimmune diseases such as inflammatory bowel disease (IBD), celiac disease, lupus and multiple sclerosis.

Psoriasis is an inflammatory condition that appears as itchy and scaly patches on the skin. It affects more than 30% of the adults in the U.S.

It sometimes goes through cycles, with weeks or months of flare-ups and then a period of relief for a while. Factors such as infections, cuts, or burns and certain medications can trigger flares.

"Though plaques are visible to the skin, psoriasis is more than skin deep. Currently, we have powerful treatments that control skin symptoms, but not a very good understanding of how the disease evolves from [the] skin to other areas of the body," Shruti Naik, a senior investigator of the study, told Medical News Today, explaining the aim of their research.

Earlier studies have shown that one in three people with psoriasis may have a chance of developing psoriatic arthritis that causes swollen, stiff and painful joints.

The latest study aimed to develop objective diagnostic measures to predict severe psoriasis and to identify patients who are at higher risk of developing related disorders. Researchers analyzed tissue samples from 11 psoriasis patients with moderate to severe skin lesions and compared them with samples from healthy control participants.

They then used "spatial transcriptomics," a new investigative method to understand the key drivers of psoriasis and how the condition spreads. The spatial transcriptomics technique captures the locations of affected cells and determines the molecular activity in the body.

Researchers found that in patients with moderate to severe psoriasis, gene activity increased in more than three dozen molecular pathways, which even occurred in clear skin far away from the lesions.

"Our molecular cartography unexpectedly revealed that even skin areas far away from plaques that look healthy have profound changes in their cellular and molecular makeup," Naik said.

This explains how skin inflammation from psoriasis can cause a wide-ranging impact on other parts of the body, including psoriatic arthritis, type 2 diabetes, heart disease and inflammatory bowel disease.

"This gives us unprecedented access to the molecular changes in the skin that can be used to better understand psoriasis and develop new interventions. Our atlas will also be accessible to the research and medical community, so others who wish to use it for their investigations can do so with ease," Naik said. The findings were published in the journal Science.

Psoriasis may appear as flaky patches on the skin.