Burden of disease: psoriasis and psoriatic arthritis.

Psoriatic arthritis (PsA) increases the disease burden associated with psoriasis by further diminishing quality of life, increasing health care costs and cardiovascular risk, and potentially causing progressive joint damage. The presence of PsA influences psoriasis treatment by increasing overall disease complexity and, within the framework of current guidelines and recommendations, requiring the use of conventional disease-modifying anti-rheumatic drugs or tumor necrosis factor-α inhibitors in order to prevent progressive joint damage. Despite its important impact, PsA is still under-diagnosed in dermatology practice. Dermatologists are well positioned to recognize and treat PsA, given that it characteristically presents, on average, 10 years subsequent to the appearance of skin symptoms. Regular screening of psoriasis patients for early evident joint symptoms should be incorporated into daily dermatologic practice. Although drugs effective in PsA are available, not all patients may respond to treatment, and others may lose their initial response over time. New investigational therapies, such as inhibitors of interleukin-17A, interleukin-12/23, Janus kinase 3, or phosphodiesterase-4, may address unmet needs in psoriatic disease, with further research needed to determine the role of these agents in reducing joint damage and other comorbidities.