Comparison of the hunting reaction in normals and individuals with Raynaud's disease.

Cold-induced vasodilation (CIVD or hunting reaction) was studied in eight subjects with Raynaud's disease, an idiopathic vasospastic disorder of the peripheral vasculature, and in nine normal subjects using 5, 10, 15 +/- 1 degree C water bath immersions of the right middle finger. Differences between Raynaud's and normal subjects were only marginal at 5 degrees C; at 10 degrees C, Raynaud's subjects showed a longer time to the first rise of skin temperature, had lower mean digital skin temperature, and a lower amplitude of their digital skin temperature during CIVD; at 15 degrees C, Raynaud's subjects had a longer time to first rise, lower number of CIVD cycles, and a lower recovery temperature.