Psoriasis is a chronic relapsing prevalent inflammatory disease affecting 2-4% of the world's population. Severe psoriasis is a disabling disease affecting the physical and emotional well being of patients, and its effect on quality of life is similar to that seen with other major medical diseases such as diabetes, rheumatoid arthritis, and cancer. Lately, it is increasingly being recognized that psoriasis is not merely a skin disease but is probably associated with other co-morbidities such as psoriatic arthritis, Crohn's disease, the metabolic syndrome and cardio-vascular diseases (CVD). The metabolic syndrome is a combination of diabetes mellitus type II (or insulin resistance), hypertension, central obesity, and combined hyperlipidemia (elevated LDL; decreased HDL; elevated triglycerides). As the literature linking psoriasis and the metabolic syndrome expands, also reports of an increased rate of CVD mortality in psoriasis patients accumulates. These data emphasize that metabolic dysregulations are the leading risk factors for occlusive vascular events and early death in patients with severe psoriasis. Progress in understanding the pathogenesis of these apparently diverse diseases has discovered that low-grade systemic inflammation might be the common physiological pathway that may provide the biological plausibility of the associations discovered in the epidemiological studies. Since some of these co-morbidities often become clinically apparent years after the onset of psoriasis we assume that controlling systemic inflammation might prevent or reverse some of these co-morbidities.
Presently there is no study in psoriasis that shows that a "systemic" co-morbidity can be prevented or treated by reversing skin inflammation.