Psoriatic arthritis (PsA) is a complex musculoskeletal disorder. Its clinical features include psoriasis, peripheral arthritis, spinal involvement, enthesitis, and dactylitis. Typically, skin lesions precede osteoarticular lesions, although osteoarticular lesions can precede skin lesions in some cases. This study aimed to investigate the onset pattern of PsA, the time interval between the occurrence of skin and osteoarticular lesions, and the treatment status of PsA. A total of 64 patients with PsA who had been assessed according to the CASPAR criteria were enrolled. Of those, 75% had a typical lesion onset pattern where skin lesions preceded osteoarticular lesions (skin leading) and 16% had an osteoarticular leading lesion pattern. The mean time interval between the onset of lesions in patients with the skin leading pattern was 14.2 years and that in patients with the osteoarticular leading pattern was 4.5 years. Non-steroidal anti-inflammatory drugs were prescribed to 39% of patients, conventional synthetic disease modifying antirheumatic drugs (DMARDs) to 64%, and biologic DMARDs to 51.5%. In conclusion, there were several cases where osteoarticular lesions preceded skin lesions in PsA; therefore, care should be taken with regard to oligo- or poly-arthritis patients with a negative rheumatoid factor without the presence of skin lesions.
Part of the book: Psoriasis