Objectives: Objective outcome measures of systemic sclerosis (SSc)-related Raynaud’s phenomenon (RP) are badly needed. Our objectives were to validate the thermographic response to a standard hand cold challenge as an outcome measure by assessing sensitivity to change, and to explore mobile phone thermography as a feasible, ambulatory tool.

Method: Twelve patients with an SSc-spectrum disorder admitted for intravenous iloprost infusions underwent a standard cold challenge before and after one infusion. Thermographic measurements included area under the rewarming curve (AUC) and maximum rewarming temperature (MAX). Before and during another infusion, each patient underwent monitoring of finger skin temperature by two methods: continuous thermocouple recording (standard method) and mobile phone thermography.

Results: All cold challenge summary measures, including AUC and MAX, increased after iloprost (most not significantly). However, when the response curves were modelled after averaging across fingers (linear mixed models, three versions), significant change was detected. For example, with Model 1 (no interaction between period and time), temperature was on average 1.67ºC [95% confidence interval (CI) 1.49–1.85, p < 0.001] higher post-iloprost. Mobile phone and thermocouple temperature measurements showed a strong estimated latent correlation (0.88, 95% CI 0.81–0.92). The estimated increases/hour were 0.25ºC (95% CI 0.05–0.45) for the thermocouple and 0.36ºC (95% CI 0.13–0.60) for mobile phone thermography.

Conclusion: Our pilot study suggests that the thermographic response to a cold challenge is sensitive to change and mobile phone thermography could bring feasibility to thermographic parameters as outcome measures in later-phase, large-scale, community-based clinical trials of RP.

目标： 系统性硬化症 (SSc) 相关的雷诺现象 (RP) 的客观结果测量是急需的。我们的目标是通过评估对变化的敏感性来验证对标准手冷挑战的热成像响应作为结果测量，并探索手机热成像作为一种可行的流动工具。

方法：12 名接受伊洛前列素静脉输注的 SSc 谱系疾病患者在一次输注之前和之后接受了标准的冷挑战。热成像测量包括复温曲线下面积 (AUC) 和最大复温温度 (MAX)。在另一次输注之前和期间，每位患者通过两种方法监测手指皮肤温度：连续热电偶记录（标准方法）和手机热成像。

结果：伊洛前列素后所有冷挑战总结测量，包括 AUC 和 MAX，均增加（大多数不显着）。然而，在对手指进行平均后对响应曲线进行建模时（线性混合模型，三个版本），检测到显着变化。例如，对于模型 1（周期和时间之间没有相互作用），使用伊洛前列素后温度平均高 1.67ºC [95% 置信区间 (CI) 1.49–1.85，p < 0.001]。手机和热电偶温度测量显示出很强的估计潜在相关性（0.88, 95% CI 0.81–0.92）。热电偶的估计增量/小时为 0.25ºC (95% CI 0.05–0.45)，手机热成像的估计增量为 0.36ºC (95% CI 0.13–0.60)。

结论：我们的初步研究表明，热成像对寒冷挑战的反应对变化很敏感，手机热成像可以为热成像参数带来可行性，作为后期、大规模、基于社区的 RP 临床试验的结果测量。