Nail ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review

To systematically review the role of ultrasound (US) in the assessment of the joint-enthesial-nail apparatus in patients with psoriatic arthritis (PsA) or psoriasis (PSO) in terms of prevalence, diagnosis, prognosis, monitoring and treatment. A systematic literature review was conducted through medical databases (PubMed, Embase) and the grey literature up to February 2018. The main areas of application of nail US were first identified, allowing the development of research questions, which were rephrased following the PICOs methodology to develop inclusion criteria. Of the 585 studies produced by PubMed and Embase searches, 17 studies met the criteria for inclusion. Five additional studies were included: 1 from the hand search and 4 from the 2016–2017 ACR and EULAR congresses. The prevalence of nail plate changes varied from