Cold urticaria in tropics: A clinico-epidemiological study from North India.

Background Cold urticaria (ColdU) is classified as a subtype of chronic inducible urticaria characterised by recurring pruritic wheals and/or angioedema upon exposure to cold stimuli. However, very limited data is available on ColdU specifically among Indians. Objectives The aim of this study was to describe the clinico-epidemiological characteristics and treatment response in North Indian patients diagnosed with ColdU. Materials and Methods The clinical records of patients diagnosed with ColdU past 5 years (January 2018 to December 2022) were retrospectively reviewed. Data including patient demographics, clinical manifestations, comorbidities, laboratory findings, and treatment response were collected and analysed. Results Among the 1780 urticaria patients included in our study, only 15 cases of cold-induced urticaria were identified. ColdU was classified as typical in all but three patients. The mean age of affected individuals was 36 ± 18 years (20-65 years) and eight patients (53.3%) were males. Mean disease duration at presentation was 18 ± 27 months (3 months-4 years). Two patients experienced cold-induced angioedema and one patient had hypotensive episodes following cold exposure. Twelve patients demonstrated positive results in the ice cube provocation test. Of 15, only 6 (40%) achieved complete control of symptoms with standard dosing of second generation anti-histamines while six patients (40%) required titration to higher doses and three patients (20%) were initiated on cyclosporine therapy, resulting in remission. Limitations Retrospective study design and possibility of selection bias. Conclusion Due to India's predominantly tropical climate, ColdU prevails at lower levels compared to the western regions. ColdU is likely underdiagnosed in India, possibly dismissed as chronic spontaneous urticaria. The management of ColdU involves a combination of protective measures against cold exposure and the use of anti-histamines to control disease activity. This retrospective study provides valuable insights into the clinico-epidemiological characteristics and treatment response of north Indian patients with ColdU.