What is "psoriatic arthritis"

n. a form of rheumatoid arthritis usually affecting fingers and toes and associated with psoriasis

Psoriatic arthritis (also arthritis psoriatica, arthropathic psoriasis or psoriatic arthropathy) is a type of inflammatory arthritis that will develop in between 6 and 42% of people who have the chronic skin condition psoriasis. Psoriatic arthritis is classified as a seronegative spondyloarthropathy and therefore occurs more commonly in patients with tissue type HLA-B27.