Raynaud phenomena and finger systolic pressure during cooling.

Finger systolic pressure (FSP) can be measured after finger cooling with a water perfused double-inlet-plastic cuff on the midphalanx of a finger and a mercury-in-rubber strain gauge on the outer phalanx. After finger cooling to 20, 15 and 10 degree C eighteen females with primary Raynaud phenomena had a significantly greater reduction in FSP than twenty-two normal females, but only eleven of the eighteen females (60%) with Raynaud phenomena showed digital arterial closure. Standardized body cooling for 20 min before finger cooling enhanced the reaction in both groups. As only females with Raynaud phenomena showed digital artery closure, the diagnostic value of a combined finger and body cooling test in primary Raynaud phenomena is high. The reproducibility of the test is acceptable.