Capillaroscopy.

Raynaud's phenomenon (RP) is the most common and significant clinical condition with an indication for a microvascular analysis to be carried out as soon as possible. Microvascular involvement is a key feature of RP and several rheumatic diseases are characterised by the presence of RP. Nailfold capillary microscopy shows an impressive cost/effectiveness ratio: it is simple, non-invasive and inexpensive. Well recognised nailfold videocapillaroscopic patterns (NVC) have been described mainly in systemic sclerosis (SSc) patients with secondary RP. The peripheral microvascular damage in SSc is characterised by increasing structural alterations of the capillaries (giant capillaries and microhaemorrhagies) with a progressive decrease in their density. The detection of the scleroderma NVC pattern allows an early distinction between the primary RP (functional, not disease associated) and the secondary RP (disease associated). Other major NVC patterns have been described in the field of rheumatic diseases. Interestingly, correlations are evident between the NVC and the clinical symptoms, severity of the disease and the laboratory findings.