title: Increased risk of psoriasis following chronic rhinosinusitis without nasal polyps: a population-based matched-cohort study.
abstract: BACKGROUND
  Although chronic rhinosinusitis without nasal polyps (CRSsNP) and psoriasis both share immunological disturbances as pathological factors, no prior study has investigated the risk for psoriasis among patients with CRSsNP.
  
  
  OBJECTIVE
  To investigate the subsequent risk for psoriasis following a diagnosis of CRSsNP by utilizing a cohort study design and a population-based dataset in Taiwan.
  
  
  METHODS
  In total, 13 242 subjects with CRSsNP were included in the study cohort and 39 726 subjects were randomly extracted for the comparison cohort. We individually tracked each individual in this study (n = 52 968) for a 5-year period following their index date to identify those subjects who received a subsequent diagnosis of psoriasis. Cox proportional hazards regression analysis was conducted to calculate the 5-year risk of subsequent psoriasis following a diagnosis of CRS among the sampled subjects.
  
  
  RESULTS
  The incidence rate of psoriasis during the 5-year follow-up period was 1·41 [95% confidence interval (CI) 1·14-1·71] per 1000 person-years and 0·69 (95% CI 0·59-0·81) per 1000 person-years for the study and comparison cohort, respectively. Stratified Cox proportional hazards regression revealed that the hazard ratio for psoriasis during the 5-year follow-up period for subjects with CRSsNP compared with the control group was 2·01 (95% CI 1·54-2·62) after adjusting for monthly income, geographical region, hypertension, diabetes, coronary heart disease and hyperlipidaemia, and censoring the cases who died during the 5-year follow-up period.
  
  
  CONCLUSIONS
  This study detected an increased risk for psoriasis among patients with CRSsNP.
authors.affiliation: School of Public Health, Taipei Medical University, Taipei, Taiwan.
authors.forename: J J
authors.initials: JJ
authors.lastname: Keller
authors.forename: C-S
authors.initials: CS
authors.lastname: Wu
authors.forename: H-C
authors.initials: HC
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002908:Chronic Disease; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps; D011565:Psoriasis / Q000453:epidemiology / Q000209:etiology*; D012220:Rhinitis / Q000150:complications*; D012852:Sinusitis / Q000150:complications*; D055815:Young Adult