Millions of Americans suffer from psoriasis, a common inflammatory skin condition that puts them at increased risk for cardiovascular disease. But exactly why this occurs wasn’t known, until now.

Using genetically engineered mice, researchers have been able to demonstrate that the same autoimmune disease that causes inflamed patches on the skin also causes inflammation of the heart.

First, researchers at Case Western Reserve University of Medicine were able to use genetic engineering to develop a skin condition in mice that is similar to human psoriasis. Then they teamed up with the colleagues in the university’s cardiovascular department and compared these mice with normal mice, to see if they developed cardiac complications that mimicked those seen in human psoriasis patients.

They found that the mice with the psoriasis-type condition had blood that was more likely to clot than the normal mice, and that the walls of the coronary arteries in the genetically engineered mice also became inflamed. These findings are similar to what happens to adult humans with coronary heart disease.

But perhaps most important to patients with psoriasis, the researchers were also able to demonstrate that reversing the psoriasis decreased the risk of heart disease.