Diagnosis of Raynaud's phenomenon assisted by color charts

A simple questionnaire, combined with color charts consisting of a 12-point color scale and a series of photographs illustrating blanching and cyanosis, has been developed to assist in the diagnosis of Raynaud's phenomenon (RP). The value of the color charts alone was first tested on a group of 48 patients with RP in whom the RP attacks were witnessed by the investigators (gold standard) and on a group of 246 RP negative subjects; the results showed a sensitivity of 90% and a specificity of 100%. A short RP diagnostic test was then devised by combining the questionnaire and color chart responses, which increased the sensitivity to 100% in our gold standard group of RP positive subjects. Further evaluation of this RP diagnostic test on a sample of 325 subjects whose RP status was unknown demonstrated that the majority could be classified as clearly RP positive or negative with only 4 subjects in the intermediate category.