Assessment and treatment of psoriatic spondylitis.

The axial element of psoriatic arthritis has suffered from a lack of validated outcome measures. Therefore, clinical trials demonstrating efficacy with newer therapies-such as biologic disease-modifying drugs, which for the first time have shown evidence of reduction in radiologic damage in peripheral arthritis-have focused on peripheral arthritis and rash, ignoring other outcomes. This article discusses recent advances in assessment measures and therapy recommendations borrowed from the ankylosing spondylitis literature due to the continuing absence of adequate trials examining axial involvement in the psoriatic arthritis population.