Cold-induced whealing in patients with typical ColdU is linked to
markedly increased blood perfusion and PPG amplitudes
Patients with typical ColdU had high blood perfusion at skin sites that
developed wheals in response to ICT, with an average PPG amplitude of
41.4·10-4 ± 5.8·10-5 AU. This was
markedly higher than their blood perfusion at baseline (PPG amplitude:
6.2·10-4 ± 5.7·10-6 AU) as well as
that of cold-exposed skin sites in patients with atypical ColdU (PPG
amplitude: 9.9·10-4 ± 1.4·10-4 AU)
and HCs (PPG amplitude: 9.5·10-4 ±
1.5·10-4 AU). Patients with atypical ColdU and HCs did
not develop wheals at CST skin sites.
Patients with typical ColdU exhibit distinct pre-post CST changes
in PPG amplitudes The ratio of post-provocation and baseline PPG amplitudes
(R PPG) was markedly higher in typical ColdU
patients (6.7 ± 0.3) than in atypical ColdU patients (1.9 ± 0.4) and HCs
(1.9 ± 0.5). Of 39 typical ColdU patients, 38 (97.4%) had anR PPG >3, but only 3 of 24 patients
with atypical ColdU (12.5%) and one of 15 (6.7%) HCs (Figure
4 ).