Supplemental material
Figure 1. Scatterplot of R PPG and CTT.
ICT , ice cube test, TT , TempTest®,CTT , critical temperature threshold
The correlation coefficient (CC) of R PPG of
ICT/TT-positive patients and the CTT is 0.12, at once the CC ofR PPG of all study objects and the CTT is 0.70,
the CC of post CST PPG amplitudes for typical ColdU and CTTs is 0.15.
Figure 2. Typical PPGs before (A, C) and after ICT (B, D) for a
healthy person (A, B) and a ColdU patient (C, D).
Figure illustrates PPGs in one of the ColdU patients with positive SPT
and one of the HCs. The frequency of the pulses indicates the heartbeat.
The pulse shape may be associated with the state of tissue and its
pathologies. Before ICT, PPG amplitudes for ColdU and healthy volunteers
have similar values but after cold exposure they grow in a different
way. The relative increase of PPG amplitude is much higher for ColdU
patients than for healthy ones. To quantify the effect of exposure to
cold on microcirculation, we introduced the valueR PPG as a ratio of PPG amplitudes after and
before the ICT.
ColdU, cold urticaria, ICT, ice cube test, PPG ,
photoplethysmography
Orcid
Sofia Serdotetskova https://orcid.org/0000-0001-8472-115
Alexander Machikhin https://orcid.org/0000-0002-2864-3214
Daria Fomina https://orcid.org/0000-0002-5083-6637
Mikhail Volkov https://orcid.org/0000-0002-9658-9467
Anastasia Guryleva https://orcid.org/0000-0003-2239-3725
Mojca Bizjak https://orcid.org/0000-0003-2595-468X
Valeriya Bukova https://orcid.org/0000-0001-9564-4308
Marina Lebedkina https://orcid.org/0000-0002-9545-4720
Olga Mukhina https://orcid.org/0000-0002-3794-4991
Gerelma Andrenova https://orcid.org/0000-0001-7053-3900
Irina Mukatova https://orcid.org/0000-0002-5804-8643
Inna Danilycheva https://orcid.org/0000-0002-8279-2173
Marcus Maurer https://orcid.org/0000-0002-4121-481X