Determination of fingertip lacticemy before and after cold stimulus in patients with primary Raynauds phenomenon and systemic sclerosis

Abstract

Objective. Establishing a cold stimulus test based on the measurement of finger tip lacticemy (FTL) in Raynaud's phenomenon (RP).Methods. Twenty-seven controls and 79 patients with RP [30 systemic sclerosis (SSc) and 49 isolated RP] were studied. The latter were further classified into probable primary RP (PPRP) and probable secondary RP (PSRP). FTL was determined before (pre-CS) and after (post-CS) a cold stimulus and the percentage difference was designated DeltaCS-FTL.Results. Pre-CS-FTL was marginally higher in SSc patients than in isolated RP and controls. Post-CS-FTL was significantly higher in SSc and PSRP than in PPRP and controls. SSc and PSRP patients had higher post-CS-FTL than pre-CS-FTL (positive DeltaCS-FTL) while controls presented a negative DeltaCS-FTL. Post-CS-FTL had a heterogeneous behavior in patients with PPRP.Conclusion. CS-FTL test was shown to be an easy method for evaluation of fingertip effective perfusion before and after a cold stimulus. Further studies are warranted to test its possible clinical application in discriminating between patients with SSc and controls, as well as between patients with PPRP and PSRP.