Raynaud's phenomenon (primary or secondary to systemic sclerosis). The usefulness of laser-Doppler flowmetry in the diagnosis.

Background. Raynaud's phenomenon (RP) consists of painful vascular spasms of the extremities stressed by cold exposure. It is often a symptom, in many cases the onset, of systemic sclerosis (SSc). The aim of this study was to evaluate the role that laser-Doppler flowmetry (LDF) could have in the differential diagnosis of these disorders and to characterize the functional behaviour of the microvessels in RP. Methods. In this study we examined 52 patients (five males and 47 females, aged 17-57) affected by primary RP, 21 patients (three males and 18 females, aged 31-63) affected by RP secondary to SSc as defined by Wouda in 1987 and 20 healthy subjects (three males and 17 females, aged 26-58) by means of LDF with an appropriate cold-test (11°C for 2 min). Results. We show that the cold test applied at hand level can distinguish RP patients from healthy subjects. Data show that basal blood flow of patients affected by SSc is diminished in its medium value and presents a typical tracing without vasomotion in comparison to healthy subjects and also to patients affected by primary RP. On the basis of our data among the primary RP patients we can also distinguish a group that show basal blood flow tracing very similar to that of sclerodermic patients. These subjects should be carefully followed-up. Conclusions. In conclusion, it could be stimulating for the future to introduce LDF as a complementary method for the diagnosis of RP and possibly for early discrimination between the primary disease and that secondary to SSc.