Psoriatic arthritis (also arthropathic psoriasis or psoriatic arthropathy)) is a type of inflammatoryarthritis that affects around 5-7% (according to Oxford Handbook of Clinical Medicine) of people suffering from the chronic skin condition psoriasis. It occurs more commonly in patients with tissue type HLA-B27. Treatment of psoriatic arthritis is similar to that of rheumatoid arthritis. More than 80% of patients with psoriatic arthritis will have psoriatic nail lesions characterised by pitting of the nails, or more extremely, loss of the nail itself (onycholysis). Psoriatic arthritis is said to be a seronegativespondyloarthropathy.
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