Clinical utility of nailfold capillaroscopy

Nailfold capillaroscopy (NFC) is a simple noninvasive microscopic technique used to identify characteristic morphological abnormalities in the nailfold capillaries. The presence of this microvasculopathy appears to be of fundamental importance in the pathological processes that underlie the scleroderma spectrum disorders (including dermatomyositis and antisynthetase myositis). This review discusses the different methodologies and techniques in performing NFC and stresses the diagnostic utility achieved with simple 'bedside' techniques utilising the ophthalmoscope, dermatoscope or smart phone. Recent advances in reporting abnormal microvascular patterns and vascular metrics (e.g. capillary density and dropout) are discussed. The aetiopathogenesis of the microvasculopathy is currently unknown but its close association with Raynaud Phenomena and specific autoantibodies together with recent observations from sequential NFC allows speculations on its possible mechanism. Finally, future developments in the use of NFC as a possible biomarker in the management of the scleroderma spectrum disorders are discussed, with a recommendation that NFC becomes more widely available, particularly in rheumatological, immunological and dermatological practice. NFC provides a clinically accessible window on the pathologic process fundamental to scleroderma-related disease.