The skin lesions of psoriasis are bad enough. Dr. Kristine E. Nograles and coauthors at The Rockefeller University in New York described the cellular changes in four steps: thickened epidermis from accelerated growth of skin cells, reduced granular layer caused by failure of cells to differentiate properly, redness from blood vessel dilation, and high numbers of cells associated with inflammation. “Psoriasis is a complex genetic disorder,” they explained, “which means that it is a multi-factorial heritable disease that is influenced by multiple genes and environmental factors.” It has been known for some time that family history is a risk factor for psoriasis. Now that the human genome has been sequenced, several different gene regions are associated with the disease, and three of these involve specific inflammatory pathways.
Mild cases can be treated successfully with skin preparations. More severe cases can be a sign of deeper problems. Dr. Ramin Ghazizadeh of the Academic Dermatology and Skin Care Institute in Chicago, Illinois, and his colleagues in Japan reported that psoriasis and cardiovascular disease share many of the same mechanisms. They wrote, “it is now widely believed that psoriasis is not just a skin disease but a systemic inflammatory process.”
At the cellular level, arteries with atherosclerosis and skin with psoriasis lesions have a lot in common, according to Ghazizadeh. Inflammatory cytokines and infiltrating white blood cells characterize both conditions, which often occur together.
Dr. Aldona Pietrzak and colleagues in Poland reported that lipid metabolism disturbances are responsible for the increased risk of cardiovascular disease, high blood pressure, atherosclerosis, diabetes type 2, obesity, chronic obstructive pulmonary disease, cancer and depression in patients with psoriasis. In the skin, lipids serve important functions as structural components and in protective skin oils. Psoriasis plaques have increased levels of total lipids, phospholipids, triacylglycerols, and cholesterol. These same lipids are increased in the blood of psoriasis patients.