The Established and Evolving Role of Nailfold Capillaroscopy in Connective-Tissue Disease

Abstract

Nailfold capillaroscopy (NFC) is a low-cost, non-invasive, rapid, highly specific and reproducible investigation well established in the diagnosis of systemic sclerosis and related conditions. This chapter will detail the relevant underlying scientific principles that underpin the investigation, the methods for performing NFC, the range of abnormalities that can be present and the currently available classification criteria before moving on to discuss the various established and emerging applications as relevant to the connective tissue diseases. In addition to its role in the diagnosis of SSc, highlighted by its inclusion in the most recent ACR/EULAR consensus classification criteria, NFC has been shown to predict disease activity, many organ-specific complications such as digital ulcers, pulmonary hypertension and interstitial lung disease, and even mortality. It is emerging as a useful investigation in other CTDs characterised by microvasculopathy, such as in the idiopathic inflammatory myopathies and mixed connective tissue disease, as well as being studied as a serial investigation in patients to act as a potential biomarker and measure of treatment efficacy. NFC can contribute to the earlier identification of patients with CTDs with clinically important complications and if applied accurately, therefore, can help improve outcomes in these often challenging diseases