title: Allergic rhinitis and associated risk of migraine among children: a nationwide population-based cohort study.
abstract: BACKGROUND
  Increased frequency of migraine was reported in adults with allergic rhinitis (AR). Although migraine is less common in children than in adults, it can begin in early childhood and persist into adulthood. We conducted this population-based cohort study to investigate the incidence and subsequent risk of migraine in children with AR.
  
  
  METHODS
  From 2000 to 2007, 461,850 children with recently diagnosed AR and 460,718 non-AR controls were included in the study. By the end of 2008, incidences of migraine in both cohorts, the AR to non-AR cohort hazard ratios (HRs), and confidence intervals (CIs) were measured.
  
  
  RESULTS
  The incidence of migraine during the study period was 3.2-fold higher in the AR cohort (95% CI, 2.97 to 3.46) than in the non-AR cohort (11.4 vs 3.49 per 10000 person-years). The risk was greater for boys than for girls, and for children aged <6 years. The HR for migraine in children with AR was 1.44 (95% CI, 1.31 to 1.58) for those with ≤2 annual AR-related medical visits, whereas, 14.8 (95% CI, 13.6 to 16.2) for those with >4 visits (p < 0.0001, the trend test). The risk of migraine development in the AR cohort was highest within the first year after AR diagnosis (HR 4.89; 95% CI, 3.98 to 6.00). Children with AR were more likely to have migraine without aura than migraine with aura.
  
  
  CONCLUSIONS
  Children with AR had a higher incidence and subsequent risk of migraine. Physicians should be more aware of migraine in children with AR who complain of headache.
authors.affiliation: Children's Hospital, China Medical University Hospital, Taichung, Taiwan.
authors.forename: I-Chung
authors.initials: IC
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, Taiwan.|Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Jeng-Dau
authors.initials: JD
authors.lastname: Tsai
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.|Institute of Biostatistics, China Medical University, Taichung, Taiwan.
authors.forename: Cheng-Li
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.|College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Te-Chun
authors.initials: TC
authors.lastname: Shen
authors.affiliation: Institute of Biostatistics, China Medical University, Taichung, Taiwan.
authors.forename: Tsai-Chung
authors.initials: TC
authors.lastname: Li
authors.affiliation: Children's Hospital, China Medical University Hospital, Taichung, Taiwan.|College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chang-Ching
authors.initials: CC
authors.lastname: Wei
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008881:Migraine Disorders / Q000453:epidemiology*; D044382:Population Groups; D065631:Rhinitis, Allergic / Q000453:epidemiology*; D012306:Risk; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology
keywords: allergic rhinitis; children; cohort study; confidence intervals; hazard ratios; migraine