It is classified as a type of seronegative spondyloarthropathy .
Skin changes consistent with psoriasis ( e.g. , red , scaly , and itchy plaques ) frequently occur before the onset of psoriatic arthritis but psoriatic arthritis can precede the rash in 15 % of affected individuals .
arthritis is classified as a type of seronegative spondyloarthropathy .
Skin changes consistent with psoriasis ( e.g. , red , scaly , and itchy plaques ) frequently occur before the onset of psoriatic arthritis but psoriatic arthritis can precede the rash in 15 % of affected individuals .