Skin and bone: the pathogenetic relationship between psoriasis and psoriatic arthritis.

Our current understanding of the relationship between psoriasis and psoriatic arthritis remains incomplete, though the evidence from the clinical setting, response to therapeutics, epidemiology, genetics, imaging, and immunopathologic models suggest that they make likely share a common pathogenesis. Psoriatic disease can no longer be thought of as a condition limited to skin and joints. Rather, it must be considered a multi-faceted disorder in which systemic inflammation plays a central role. There is now convincing evidence that individuals with psoriasis have a higher prevalence of co-morbid disease, particularly cardiovascular risk factors, metabolic disorders, and other immune-mediated inflammatory diseases. The cutaneous manifestations of psoriasis place dermatologists in a crucial and privileged role--one that affords us the potential for early detection of associated co-morbid conditions through screening and perhaps impact disease course and clinical outcomes.