title: Influence of air temperature variations on incidence of epistaxis.
abstract: OBJECTIVE
  Epistaxis is the most common ear, nose, and throat emergency observed in the emergency department (ED). An increased frequency of this condition has been observed during cooler months, but the results of available studies are controversial. The aim of this study was to investigate the seasonality and association of epistaxis presentations to a large urban ED with variations of air temperature and humidity.
  
  
  METHODS
  This study was a retrospective case series. Information on all the patients who presented for epistaxis in the ED of the Academic Hospital of Parma during the years 2003-2012 and ages ≥ 14 years were retrieved from the hospital data base, excluding those attributable to trauma. The chronologic data of all visits were associated with climate data (air temperature and humidity) by univariate linear regression analysis.
  
  
  RESULTS
  Among the 819,596 ED patients seen throughout the observational period, 5404 were admitted for epistaxis. Of these, 5220 were discharged from the ED, whereas 184 (3.4%) needed hospital admission. A strong seasonality of epistaxis was observed, with a peak during winter. A strong negative correlation was also found between the daily number of epistaxes and the mean daily temperature in the whole population as well as in patient subgroups (those undergoing anticoagulant or antiplatelet therapy, or those with hypertension, inherited bleeding disorders, liver cirrhosis, or advanced malignancy). A weaker correlation was also found between air humidity and epistaxis but only in certain subgroups.
  
  
  CONCLUSIONS
  The results of this study provided a contribution to improve our understanding of the epidemiology of epistaxis and for specific health policies that should also be planned by considering the seasonality of nosebleed.
authors.affiliation: Emergency Department, Academic Hospital of Parma, Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Comelli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vincenti
authors.forename: Mario
authors.initials: M
authors.lastname: Benatti
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Macri
authors.forename: Denis
authors.initials: D
authors.lastname: Comelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Cervellin
mesh_terms: D000293:Adolescent; D000328:Adult; D004844:Epistaxis / Q000453:epidemiology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000639:trends; D006801:Humans; D006813:Humidity; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012621:Seasons; D013696:Temperature