The connection between heart attacks and psoriasis seems to be related to inflammation in the body, University of Pennsylvania researchers said. Both share the biological signal of high levels of C-reactive protein in the blood that is linked to inflammation.

Comparing more than 130,000 adults with psoriasis to more than 500,000 who did not have it, the study concluded that a 30-year-old with a severe form is roughly three times more likely to have a heart attack than someone without the condition.

A 30-year-old with a mild form of psoriasis had a 29 percent higher risk of a heart attack, while a 60-year-old patient with a severe case had a 36 percent higher risk, said the study, which screened out other causes of heart disease in reaching the findings.

"The magnitude of association between severe psoriasis and (heart attack) in those patients younger than 50 years is similar to the magnitude of association for other major cardiac risk factors," such as high blood pressure, high cholesterol, or diabetes, wrote study author Dr. Joel Gelfand in this week's issue of the Journal of the American Medical Association.

Emotional stress or damage to the skin can trigger psoriasis, which affects roughly 3 percent of adults. Many scientists believe it is the result of an overactive immune system that speeds up the growth cycle of skin cells, which shed too quickly and form visible, red plaques.

Some sufferers develop a form of arthritis that causes stiffness and swelling in the joints.

Though there is no cure, psoriasis can be treated with medications and exposure to light.

Gelfand said further research could pinpoint the role played by C-reactive protein or other "biomarkers."

"In the meantime, as part of good medical care, patients with psoriasis should be encouraged to aggressively address their modifiable cardiovascular risk factors," he wrote.