title: Increased risk of migraine in patients with psoriasis: A Danish nationwide cohort study.
abstract: BACKGROUND
  Psoriasis and migraine are common conditions with potential overlap of pathophysiological mechanisms. Both these diseases have been associated with increased cardiovascular risk but little is known about their interplay.
  
  
  OBJECTIVE
  We sought to investigate the link between psoriasis, and the risk of new-onset migraine, in a nationwide cohort of the Danish population.
  
  
  METHODS
  Data on all Danish citizens aged 18 years or older from January 1, 1997, to December 31, 2011, were linked at individual-level in nationwide registers. Incidence rates per 1000 person-years were calculated and crude and adjusted incidence rate ratios were estimated by Poisson regression models.
  
  
  RESULTS
  The study comprised a total of 5,379,859 individuals, including 53,006 and 6831 patients with mild and severe psoriasis, respectively, and 6243 patients with psoriatic arthritis. Fully adjusted incidence rate ratios for migraine were 1.37 (95% confidence interval 1.30-1.45), 1.55 (95% confidence interval 1.29-1.86), and 1.92 (95% confidence interval 1.65-2.22) for mild psoriasis, severe psoriasis, and psoriatic arthritis, respectively. Stratification for sex revealed increased risk of migraine in both male and female patients.
  
  
  CONCLUSIONS
  We were unable to distinguish between subtypes of migraine, eg, migraine with and without aura.
  
  
  CONCLUSIONS
  Psoriasis was associated with a disease severity-dependent increased risk of migraine independent of measured confounders. Further studies are warranted to determine the effects of antipsoriatic treatment on this association, and whether migraine modifies the psoriasis-associated risk of cardiovascular disease.
authors.affiliation: Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Department of Dermato-Allergology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark. Electronic address: alexander.egeberg@gmail.com.
authors.forename: Alexander
authors.initials: A
authors.lastname: Egeberg
authors.affiliation: Unit of Dermatology and Venereology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Lotus
authors.initials: L
authors.lastname: Mallbris
authors.affiliation: Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Danish Heart Foundation, Copenhagen, Denmark; National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Hilmar Gislason
authors.affiliation: Department of Dermato-Allergology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.
authors.forename: Lone
authors.initials: L
authors.lastname: Skov
authors.affiliation: Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Riis Hansen
mesh_terms: D000328:Adult; D015535:Arthritis, Psoriatic / Q000150:complications / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D011565:Psoriasis / Q000453:epidemiology*; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D055815:Young Adult
keywords: epidemiology; headache; inflammation; migraine; psoriasis