[Comparative evaluation of dermoscopy and capillaroscopy in Raynaud's phenomenon]

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.

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.

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.

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.