Differential risks of psoriatic arthritis development in patients with varied psoriasis manifestations: a sex- and ethnicity-specific analysis

Psoriasis is a common, chronic papulosquamous skin disease occurring worldwide, presenting at any age, and leading to a substantial burden for individuals and society. It is associated with several important medical conditions, including depression, psoriatic arthritis, and cardiometabolic syndrome. Its most common form, chronic plaque or psoriasis vulgaris, is a consequence of genetic susceptibility, particularly in the presence of the HLA-C*06:02 risk allele, and of environmental triggers such as streptococcal infection, stress, smoking, obesity, and alcohol consumption. There are several phenotypes and research has separated pustular from chronic plaque forms. Immunological and genetic studies have identified IL-17 and IL-23 as key drivers of psoriasis pathogenesis. Immune targeting of these cytokines and of TNFα by biological therapies has revolutionised the care of severe chronic plaque disease. Psoriasis cannot currently be cured, but management should aim to minimise physical and psychological harm by treating patients early in the disease process, identifying and preventing associated multimorbidity, instilling lifestyle modifications, and employing a personalised approach to treatment.

Prompt identification and treatment of psoriatic arthritis (PsA) in patients with psoriasis is critical to reducing the risk of joint damage, disability, and comorbidities. We sought to estimate PsA prevalence in patients with plaque psoriasis in 34 dermatology centers in 7 European and North American countries. Consecutive patients were evaluated by dermatologists for plaque psoriasis and subsequently by rheumatologists for PsA. PsA prevalence was estimated primarily based on rheumatologists' assessment of medical history, physical examination, and laboratory tests. Of 949 patients evaluated, 285 (30%) had PsA (95% confidence interval 27-33) based on rheumatologists' assessment. PsA diagnosis changed in 1.2% of patients when diagnostic laboratory tests were added to medical history and physical examination. Of 285 patients given the diagnosis of PsA, 117 (41%) had not been previously given the diagnosis. Bias may have been introduced by lack of standardized diagnostic criteria and unbalanced recruitment based on country populations. In this study, almost a third of patients with psoriasis seen in dermatology centers had PsA as determined by rheumatologists. More than a third of patients with PsA had not been previously given the diagnosis. Clinical evaluation alone is often sufficient basis for PsA diagnosis, but laboratory test results may be helpful in some patients. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.