Background: psoriasis and multiple sclerosis (MS) are both autoimmune T cell-mediated diseases. Some case series have suggested an association.
Objective: to investigate the potential relationship between psoriasis and MS based on a systematic review of the literature.
Methods: medline, Cochrane Library, and EMBASE searches were performed.
Results: T-helper 17 cells are involved in the pathogenesis of both psoriasis and MS. Both conditions have been associated with interleukin-23 receptor (IL23R) polymorphisms. Studies have reported psoriasis in 0.41 to 7.7% of individuals with MS. A higher rate of psoriasis compared to controls was noted in a few small MS cohorts, but the number of cases was too small to draw any firm conclusions. In two studies, including a large Canadian study of 5,031 patients with MS, there was no increased prevalence of psoriasis in patients over the control population. Family members of individuals with MS do not appear to be at increased risk for psoriasis in these studies. Psoriasis has developed during treatment for MS, and MS has developed during treatment for psoriasis.
Conclusion: although there are some common genetic linkages in psoriasis and MS, psoriasis does not appear to be more common in patients with MS or their relatives.