An Analysis of the Clinical and Photobiological Characteristics of Solar Urticaria:A 15-year Retrospective Study / 대한피부과학회지

ABSTRACT

Background@#Solar urticaria (SU) is a rare type of photodermatosis characterized by the appearance of itchy wheals and erythema within minutes after exposure to sunlight or artificial light. Only a few studies have analyzed the clinical and photobiological features of SU in Asia. @*Objective@#We aimed to analyze the clinical and photobiological characteristics of SU. @*Methods@#We retrospectively investigated the medical records of patients with SU who visited the Department of Dermatology at the Konkuk University Medical Center between January 2005 and October 2020. @*Results@#Of the 52 patients, 43 (82.7%) were men, and 9 (17.3%) were women. The mean age at onset was 17.5 years (5∼47 years), and the mean threshold time was 21.2 minutes. Among the 36 patients who underwent phototesting, the action spectrum predominantly responsible for SU was ultraviolet (UV) A only in 14 (38.9%) patients and visible light (415 nm) only in nine (25.0%) patients. Three patients (8.3%) were induced by both UVA and visible light (415 nm). In eight (22.2%) patients, the symptoms were triggered only by natural sunlight. Serum immunoglobulin E (IgE) levels were measured in 39 patients, and 21 (53.8%) patients showed elevated IgE levels. Oral antihistamine (48.1%) was the most widely used treatment, followed by oral cyclosporine (15.4%) and phototherapy (11.5%). @*Conclusion@#SU is an uncommon type of photodermatosis in Korea, with a greater prevalence in men. In this study, UVA was found to be the predominant action spectrum responsible for SU.