Management of psoriatic arthritis: Early diagnosis, monitoring of disease severity and cutting edge therapies.

Psoriatic arthritis (PsA) is a heterogeneous disease that can involve a variety of distinct anatomical sites including a patient's peripheral and axial joints, entheses, skin and nails. Appropriate management of PsA requires early diagnosis, monitoring of disease activity, and utilization of cutting edge therapies. To accomplish the former there are a variety of PsA-specific tools available to screen, diagnose, and assess patients. This review will outline the recently developed PsA screening tools, including the Toronto Psoriatic Arthritis Screening Questionnaire (TOPAS), the Psoriasis Epidemiology Screening Tool (PEST), the Psoriatic Arthritis Screening and Evaluation (PASE), and the Psoriasis and Arthritis Screening Questionnaire (PASQ). We will also review the Classification Criteria for Psoriatic Arthritis (CASPAR) and current PsA disease severity measures, such as the Disease Activity index for Psoriatic Arthritis (DAPSA), the Psoriatic Arthritis Joint Activity Index (PsAJAI) and the Composite Psoriatic Disease Activity Index (CPDAI). As is the case for PsA screening and assessment tools, there are also a variety of new therapies available for PsA. Historically, patients with PsA were treated with NSAIDS and traditional disease-modifying anti-rheumatic drugs (DMARDs). However, the ability of these medications to slow down the radiographic progression of joint disease has not been demonstrated. In contrast, anti-TNF agents, such as etanercept, infliximab, adalimumab, golimumab and certolizumab, are effective in this regard. Emerging PsA treatments include an oral phosphodiesterase 4 inhibitor, apremilast; a Janus kinase (JAK) inhibitor, tofacitinib; and several new biologics that target the IL-23/IL-17 pathway including secukinumab, brodalumab, ixekizumab, and ustekinumab. Herein we will review the mechanisms of action of these drugs, their results in clinical trials, and guidelines for administration. Lastly, treatment recommendations from the European League Against Rheumatism (EULAR) and The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) will be discussed.