Environmental Risk Factors for Pediatric Epistaxis vary by Climate Zone

Introduction and Objective: Prior studies have provided variable results regarding environmental risk factors for epistaxis. These studies were conducted in varying climate zones, which may explain discrepancies in results. The objective of this study is to investigate correlations between season, temperature, and humidity on frequency of pediatric epistaxis across climate zones.Methods: Children seen in the outpatient setting for epistaxis were identified from the 2007-2010 IBM MarketScan database. Climate zones were assigned according to International Energy Conservation Code (IECC) classification, where temperature zones in the United States and territories were assigned on an ordinal scale from 1 (tropical) to 8 (subarctic), and humidity zones were categorized as moist, dry, or marine. The control population was a sample of all well-child visits matched by age and county.Results: We identified 184,846 unique children seen for epistaxis and 1,897,012 matched controls. Moderate temperature zones were associated with lower odds of epistaxis compared with the hottest and coldest zones. Humidity was associated inversely with epistaxis rates in moderate temperature zones but was not a significant predictor of epistaxis in climates with extreme heat. Additionally, summer was associated with lower odds of epistaxis compared to winter. Interestingly, however, there were significantly higher rates of cautery procedures during summer months, driven largely by increased procedures performed in clinic, as opposed to the operating room or emergency room.Conclusions: Environmental risk factors for epistaxis vary by climate zone. The model presented reconciles prior reports and may allow for more personalized clinical management based on regional climate.