Raynaud's phenomenon. Photoelectric plethysmography of the fingers of persons with and without Raynaud's phenomenon during cooling and warming up.

A study has been made of the changes in the amplitudes shown on photoelectric plethysmographs of the fingers of one hand of controls (17 men and 17 women without Raynaud's phenomenon) during cooling and warming up of the hand. This is called the cooling and warming up test. The hands of the women appeared to cool more quickly than of the men, besides getting warm more quickly and remaining warm for a longer period. This difference is already apparent at the lowest water temperatures (6 and 3 degrees C) and may be ascribed to a difference in hand volume, with a hunting reaction due to extreme cold. The lowest values of controls appear to be useful for the clinical differentiation of patients with a serious Raynaud's phenomenon. The test is said to be positive when the values are below the lowest values of the controls. The test was performed on 50 of 58 out-patients suffering from Raynaud's phenomenon. In serious cases the severity of the disease could be assessed objectively. In less serious cases the test was sometimes negative.