Limitation of finger systolic pressure measurement as a diagnostic test for primary Raynaud's phenomenon in a female population.

The diagnostic value of measurement of the finger systolic pressure (FSP) was assessed during combined local and whole body cooling in a population-based sample of women with a medical history of primary Raynaud's phenomenon. Forty women had mild Raynaud's phenomenon and 40 had pronounced Raynaud's phenomenon. The results were compared with subjective assessments of complaints from Raynaud's phenomenon as indicated on a visual analogue scale (VAS) in the same group of women. The mean FSP at 10 degrees C was significantly lower in the patients than in 24 age- and sex-matched controls, but there was a large overlap in individual responses. The sensitivity of the FSP method was only 51% for the whole group with primary Raynaud's phenomenon. There was no significant difference in FSP at 10 degrees C between subjects with mild and those with pronounced Raynaud's phenomenon. The subjective severity of the symptoms as indicated on VAS was significantly higher in these two combined groups than in the controls. The mean VAS value was significantly higher in the group with pronounced Raynaud's phenomenon (P less than 0.01) than in that with the mild type. The low sensitivity of FSP measurement implies that this method is of limited value as a diagnostic test in subjects with primary Raynaud's phenomenon. Furthermore, there was no significant correlation between FSP and the VAS values (r = 0.23).