The ‘distal–dorsal difference’: a thermographic parameter by which to differentiate between primary and secondary Raynaud's phenomenon

摘要: Objective. To test the hypothesis that in a patient with Raynaud’s phenomenon (RP), difference of >18C between fingertips and dorsum hand [‘distal–dorsal difference’ (DDD), fingers cooler] is specific for underlying structural vascular disease as occurs systemic sclerosis (SSc), to evaluate other thermographic parameters separation secondary from primary RP. Methods. A retrospective analysis case notes thermography results patients attending thermography, primarily over 2-yr period. Multinomial logistic regression was used ascertain whether variables differed groups RP (56 patients), undifferentiated connective tissue (21 patients) SSc (45 adjustment age, sex smoking. Results. DDD any finger at 308C had positive predictive value 70%, negative 82%, identifying SSc. From multinomial regression, score derived incorporating number >18 Ca t maximum rewarming gradient. This (with suitable cut-off) 82% sensitive SSc, 73% 89%. Conclusion. Parameters (incorporating both heat cold challenge) aid prediction