Study subjects and conduct
The study was performed at the Center of Allergy and Immunology, City
Clinical Hospital No. 52 of the Ministry of Healthcare of Moscow
(Moscow, Russia) between May 2021 and February 2023 after approval by
the independent local ethics committee (protocol #06/0621). All study
participants provided prior written informed consent.
We analyzed 63 patients with expert-confirmed ColdU. Of these, 39
patients had typical ColdU confirmed by positive ICT and
TempTest® CSTs. The other 24 patients had atypical
ColdU with negative ICT and TempTest® CSTs. In both
groups, we recorded gender, age, the incidence of life-threatening
reactions like angioedema and hypotensive reactions (weakness,
dizziness, loss of consciousness), comorbid CSU, and other types of
CIndUs, frequency of allergic, autoimmune and oncological diseases,
duration of ColdU, treatment, and results of standardized validated
questionnaires (Urticaria Control Test, UCT; Dermatology Life Quality
Index, DLQI). Patients with typical and atypical ColdU were similar in
their demographic and clinical features, except for the duration of
disease, which was 24 months (range 11 to 71 months) in typical ColdU
and 212 months (range 60 to 360 months) in atypical ColdU (Table 1). We
also investigated 15 healthy controls (HCs) who had no history of
pathological reactions associated with cold exposure, and all of them
had negative CSTs.