People suffering from severe psoriasis appear to die younger than people who do not have the disease or have a mild form of it, a recent study says.

Psoriasis is a common but incurable disorder that usually causes red scaly patches on the skin. It can also cause inflammation of the joints in which case the disease is called psoriasis arthritis.

The condition has been associated with various factors, including smoking, alcohol use and diseases such as obesity, cardiovascular disease and some cancer. It can also cause significant discomfort  interfering with basic functions as sleep, work and self-care.

Now, the disease is also believed to be associated with an increased risk of death, researchers at the University of Pennsylvania, School of Medicine in Philadelphia say.

"In addition, certain systemic therapies for psoriasis may rarely be associated with mortality [death] due to chronic cumulative drug toxicity or idiosyncratic reactions, and the disease itself may lead to death in rare instances," the authors write.

Dr. Joel Gelfand, M.D., M.S.C.E. and colleagues analyzed records from database of patients who contacted health specialists in the United Kingdom between 1987 and 2002. They identified 133,568 patients with mild psoriasis with no history of treatment for the condition and 3,951 patients with severe psoriasis, where the condition affected about 10 to 20 percent of their body. These patients followed a treatment or other therapies specific for the condition.

The findings were disturbing. People with severe psoriasis had 50 percent increased risk of death compared with healthy people.

Men with severe psoriasis died an average of 3.5 years earlier than men without the condition, while women with severe psoriasis died 4.4 years earlier.

The good news is that mild psoriasis was not associated with an increased risk of death.

"Patients with severe psoriasis should receive comprehensive health assessments to enhance preventive health practices, improve overall health and decrease the risk of mortality."  

Gelfand says that further studies are needed to understand what exactly causes the increased risk of death in people with severe form of psoriasis.

"Further studies are necessary to determine the cause of excess morality in patients with severe psoriasis, how the extent of skin disease affects morality risk and whether the risk of mortality in patients with severe psoriasis is altered by various systemic therapies," the authors conclude.

The study supported by a grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases is published in the December issue of Archives of Dermatology, a journal of the American Medical Association.