In addition to itch and pain associated with plaques, patients with psoriasis often have comorbidities, including cardiovascular disease, diabetes, obesity, metabolic syndrome, risk of malignancies, fatty liver disease, and/or depression.1,2 An increased risk of death from all causes was recently demonstrated.3 Approximately 30% of patients with psoriasis develop psoriatic arthritis (PsA),4-6 a chronic, systemic inflammatory disease characterized by peripheral arthritis, enthesitis, dactylitis, axial disease, and skin and nail involvement.7-9 PsA arises through a series of complex immune signaling pathways.4 Activated T cells and macrophages play an important role in inflammatory processes through mediators such as tumor necrosis factor α (TNF-α) and various interleukin (IL) cytokines.4,7 The combination of musculoskeletal components with cutaneous disease highlights that a multidisciplinary approach may be needed for the management of individual patients.9 This narrative review discusses the efficacy and safety of systemic treatments for skin and joint manifestations in patients with psoriasis to provide dermatologists and rheumatologists with an updated summary of the benefits and risks of currently available treatments on several disease domains. We review data from pivotal clinical trials of biologic therapies that are approved by the US Food and Drug Administration for psoriasis and PsA, as well as additional clinical studies of biologics identified from PubMed and congress abstract searches through August 21, 2019.
Management of Psoriasis and PsA
Recommended therapies for psoriasis and PsA include traditional nonbiologic medications (eg, topical treatment, phototherapy, nonsteroidal anti-inflammatory drugs [NSAIDs], corticosteroids, and/or conventional disease-modifying antirheumatic drugs [DMARDs]), biologic agents, and targeted synthetic (ts) DMARDs. Because PsA is treated as a complication of psoriasis, there is an unmet need for comprehensive treatment guidelines. Recommendations for the management of PsA were recently published by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), which considered dermatologic and musculoskeletal manifestations,9 and the European League Against Rheumatism (EULAR), which focused solely on musculoskeletal manifestations.8 Because PsA is a heterogeneous disease involving multiple domains either alone or in combination, GRAPPA recommended that the goals of therapy for all patients with PsA are to achieve the lowest possible level of disease activity in all domains (peripheral arthritis, spondylitis/axial disease, enthesitis, dactylitis, skin disease, and nail disease); optimize functional status, improve quality of life and well-being, and prevent structural damage to the greatest extent possible; and avoid or minimize complications, both from untreated active disease and from therapy.9 The GRAPPA recommendations are designed to aid in the decision-making process for patients; therefore, the choice of therapy for an individual patient should address as many involved domains