Solar urticaria in Korean patients = Solar urticaria in Korean patients

다국어 초록 (Multilingual Abstract)

Background: Solar urticaria (SU) is an uncommon type of photodermatoses characterized by erythematous wheal with pruritus after sunlight exposure, which shows a female predominance. Only a few studies to analyze the clinical features of SU were reported in Asia.
Objectives: We aimed to analyze the clinical and photobiological characteristics of SU in Korea.
Methods: We retrospectively investigated the medical records of patients with SU who visited the department of dermatology, Konkuk university medical center from January 2005 to January 2020.
Results: Of a total of 44 patients, 36 (81.8%) were male and 8 (18.2%) were female. The mean age at onset was 17.6 years (range, 5-47) and the mean threshold time was 19.7 minutes. Among 32 patients who underwent phototesting, the action spectrum most commonly implicated was ultraviolet (UV) A only in 12 (37.5%), and then visible light (415nm) only was responsible for SU in 8 (25.0%). Three patients (9.4%) were induced by both UVA and visible light (415nm). Even 4 patients (12.5%) were triggered by only natural sunlight. Serum immunoglobulin E levels were measured in 33 patients, and 17 (51.5%) showed values higher than normal. The treatment most widely used were oral antihistamine (43.2%), followed by phototherapy (13.6%).
Conclusion: SU is a rare photodermatosis in Korea, which shows a male preponderance. In this study, UVA and visible light (415nm) were predominant action spectrum of SU.