IL17A and arthropathy: However, the advent of new systemic treatments, including biologic agents and small molecules, which show efficacy for skin and joint disease, lead dermatologists to ask the question: ”Could the use of treatment for skin disease also control the subclinical arthropathy?” Within the biologic agents, the TNF-α inhibitors and the more recently approved IL-23 and IL-17 inhibitors showed good efficacy both in PsA and PsO, but with different levels of response in the disease domains.