Use of thermographic criteria to identify Raynaud's phenomenon in a population setting

Objective. To assess the value of thermographic measurements of digital skin temperature after cold challenge in classifying Raynaud's phenomenon (RP) in a healthy population. Methods. One hundred seventy-five patients with RP and 404 controls were subjected to a 15 degreesC, 60 s cold challenge test. All participants were women. Digital temperature measurements were taken at baseline, immediately postimmersion, and 10 min after immersion using a portable radiometer. Results. Baseline skin temperature was a significant predictor of RP; however, the fall in temperature on immersion and the subsequent rewarming rate provided no additional information. Conclusion. Baseline skin temperature can help to predict the occurrence of RP in patients drawn from the general population, but has relatively low discriminatory power. The cold challenge test itself is of limited additional value for classification. Although objective temperature measurements show little power overall to discriminate between RP and non-RP patients, detecting low baseline digital temperature may be a useful adjunct to clinical history in classifying the disease.