title: Seasonal variation in the onset of Wegener's granulomatosis, polyarteritis nodosa and giant cell arteritis.
abstract: OBJECTIVE
  The hypothesis of a seasonal pattern in the onset of symptoms for some vasculitides has been raised in previous small studies.
  
  
  METHODS
  Using the data collected by the American College of Rheumatology (ACR) Subcommittee on Classification of Vasculitis, we specifically tested for a higher proportion of onset of symptoms in winter, lower in summer, and intermediate for the other seasons for polyarteritis nodosa (PAN) and Wegener's granulomatosis. We also tested for a higher proportion of onset of symptoms in the spring-summer months for giant cell arteritis (GCA).
  
  
  CONCLUSIONS
  The results of our study support the hypothesis of a seasonal trend for the onset of symptoms of Wegener's granulomatosis (p = 0.04) as described previously. No seasonal pattern was found for the other vasculitides studied (PAN and GCA).
authors.affiliation: Department of Medicine, Stanford University School of Medicine, CA.
authors.forename: J P
authors.initials: JP
authors.lastname: Raynauld
authors.forename: D A
authors.initials: DA
authors.lastname: Bloch
authors.forename: J F
authors.initials: JF
authors.lastname: Fries
mesh_terms: D013700:Giant Cell Arteritis / Q000503:physiopathology*; D014890:Granulomatosis with Polyangiitis / Q000503:physiopathology*; D006801:Humans; D010488:Polyarteritis Nodosa / Q000503:physiopathology*; D012621:Seasons