Evaluation of the prevalence of musculoskeletal conditions in consecutive patients with skin psoriasis: a descriptive cross-sectional study.

The association between psoriatic arthritis (PsA) and psoriasis is well known, but some have suggested that other musculoskeletal (MSK) conditions might also be more common in patients with skin psoriasis compared with the general population. The aim of our study was to describe the prevalence of a large panel of MSK conditions, in consecutive patients with psoriasis according to skin phenotype. This was a cross-sectional study. We consecutively included 148 patients, consulting for their skin psoriasis, in the dermatology department of a tertiary hospital, Hospital Cochin in Paris, France. After the scheduled consultation with a dermatologist, a rheumatologist conducted a dedicated face-to-face interview to collected data, included demographics, comorbidities, information about the psoriasis, the MSK conditions and their treatments. Of the 148 patients, 122 (82%) had at least one MSK condition. The most common condition was mechanical back pain, present in 98 (66%) patients. Nineteen (13%) patients had spondyloarthritis (SpA), of which 95% had PsA. For all MSK conditions, the dominant psoriasis phenotype was psoriasis vulgaris. The prevalence of the other phenotypes of psoriasis differed by disease. In SpA patients, the three predominant psoriasis phenotypes were: psoriasis vulgaris (82%), scalp involvement (76%) and inverse psoriasis (65%). For all MSK diseases, the prevalence was higher than expected in the general population. Our data suggest that skin psoriasis is associated with different MSK diseases, and not only PsA.