OBJECTIVE: Raynaud\'s phenomenon (RP) is a common cause for consultation. Capillaroscopy is a well-established technique to detect capillary abnormalities suggestive of a connective tissue disease, but it is sometimes unavailable. The aim of this study was to compare dermoscopy and capillaroscopy in the assessment of RP.
METHODS: This was a prospective single-centre observational study in adult patients consulting for RP at the Hôpital Nord Franche-Comté between January 2014 and June 2015. Dermoscopy was performed at dermatological consultations and capillaroscopy was prescribed. For each capillaroscopy and dermoscopy, the following parameters were examined: normal appearance, giant capillaries, avascular areas, dystrophic capillaries or tortuosity and haemorrhages. Kappa coefficients were calculated.
RESULTS: Twenty-six patients participated in this study. The kappa coefficient was 0.76 for \"normal\" status, 0.78 for tortuosity, 0.70 for giant capillaries, 0.48 for haemorrhage and 0.62 for avascular areas. The global kappa coefficient was 0.33. Detection of these abnormalities with capillaroscopy was significantly associated with abnormal dermoscopic status (P<0.05). The sensitivity of dermoscopy for the detection of \"abnormal\" capillaroscopic status was 0.87.
CONCLUSIONS: The correlation coefficients were good. Despite poor global concordance, 80% of patients had the same status, normal or abnormal, for both capillaroscopy and dermoscopy, which resulted in the same clinical management. Dermoscopy is thus a valuable tool screening for periungual anomalies and provides support for clinical examination by the dermatologist, although the reference method continues to be capillaroscopy.

Periungueal capillaroscopy is a simple and reliable non-invasive technique allowing evaluation of cutaneous microcirculation. It was promoted for decades in patients with Raynaud\'s phenomenon in order to differentiate between the benign primary Raynaud\'s phenomenon and the secondary form in connective tissue diseases, especially systemic sclerosis. Nevertheless, the value of this procedure has also been shown in numerous pathologies such as diabetes or cardiovascular diseases. This literature review points to the versatility of this useful exam and its results in a large spectrum of diseases with microvascular involvement.

Nail-fold capillaroscopy is a non-invasive tool to study the microcirculation and is increasingly being used in dermatology, angiology and rheumatology. More recently, the use of video-capillaroscopy has allowed computer storage of capillaroscopic images (video-capillaroscopy), enabling evaluation of changes in capillaroscopic abnormalities during the follow-up of patients with systemic sclerosis or mixed connective tissue disease. Qualitative and quantitative assessment of the nail-fold dermal capillaries and of their organization can readily distinguish between a normal capillaroscopic pattern in primary Raynaud phenomenon and a specific sclerodermic pattern in secondary Raynaud phenomenon carrying a very high risk of systemic sclerosis. Apart from its important role as a diagnostic tool for distinguishing between primary and secondary Raynaud phenomenon, capillaroscopy is now used to predict the risk of development of digital ulcers and of future visceral complications in patients with systemic sclerosis. Moreover, nail-fold capillaroscopy is essential for differential diagnosis between connective tissue diseases, for the etiologic diagnosis of digital necrosis and diffuse interstitial lung disease, and in sclerodermiform syndromes.

About ten to fifteen percent of the French population suffer from Raynaud\'s phenomenon. Most of the time, it is considered as primary Raynaud\'s phenomenon, without underlying disease. The aim of this expert consensus from the \"microcirculation group\" for the French Society of Vascular Medicine and the French Society for Microcirculation, was to define clinical guidelines in patients consulting for Raynaud\'s phenomenon. The recommended minimal screening includes clinical examination, nailfold capillaroscopy and antinuclear antibodies. In particular, the aim of this screening is to identify patients with a significant risk for scleroderma, who would need a careful follow up.