title: Spring season birth is associated with higher emergency department admission for acute allergic reactions.
abstract: BACKGROUND
  Acute allergic reactions are important causes of emergency department (ED) admission, imposing a significant clinical and organizational burden. Since the season of birth is linked with early exposure to allergens, this study was aimed to establish whether an association exists between season of birth and incidence and severity of acute allergic reactions in the ED.
  
  
  METHODS
  The electronic hospital database was searched to identify all consecutive adult patients who were admitted to the ED for acute allergic reactions (acute urticaria, acute angioedema, urticaria-angioedema and anaphylaxis) during a 1-year period.
  
  
  RESULTS
  The final study population consisted in 588 patients (328 women and 260 men; mean age 43 ± 18 years, range 16-96 years). Increased frequency of ED admission was observed for patients born in spring, whereas the lowest frequency was found for those born in autumn. Patients born in spring exhibited 1.19 and 1.12 higher risk of ED admission for acute allergic reactions compared to those born in autumn and in all other seasons, respectively. This difference remained significant in patients with allergic reaction attributable to drugs and in those with unknown triggers, whereas no pattern of seasonality was observed in patients with allergic reactions attributable to aliments, hymenoptera, chemicals or inhalants. Patients born in spring also exhibited 1.86 and 1.52 higher risk of being admitted to the ED for severe acute allergic reactions compared to those born in autumn and in all other seasons, respectively.
  
  
  CONCLUSIONS
  Patients born in spring appear particularly vulnerable to allergic reactions requiring ED visit.
authors.affiliation: Emergency Department, Academic Hospital of Parma, Parma, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Cervellin
authors.affiliation: Emergency Department, Academic Hospital of Parma, Parma, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Schirosa
authors.affiliation: Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy.
authors.forename: Ruggero
authors.initials: R
authors.lastname: Buonocore
authors.affiliation: Department of Clinical and Experimental Medicine, Academic Hospital of Parma, Parma, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Nouvenne
authors.affiliation: Department of Clinical and Experimental Medicine, Academic Hospital of Parma, Parma, Italy.
authors.forename: Loris
authors.initials: L
authors.lastname: Borghi
authors.affiliation: Department of Clinical and Experimental Medicine, Academic Hospital of Parma, Parma, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Meschi
authors.affiliation: Laboratory of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy. Electronic address: glippi@ao.pr.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens; D000707:Anaphylaxis / Q000453:epidemiology* / Q000276:immunology; D000799:Angioedema / Q000453:epidemiology* / Q000276:immunology; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004781:Environmental Exposure; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D036801:Parturition; D012621:Seasons; D012720:Severity of Illness Index; D014581:Urticaria / Q000453:epidemiology* / Q000276:immunology; D055815:Young Adult
chemical_list: D000485:Allergens
keywords: Allergy; Anaphylaxis; Emergency department; Emergency medicine; Epidemiology