title: Chronic urticaria.
abstract: OBJECTIVE
  To review the pathophysiology of chronic urticaria in light of recent evidence for it being an autoimmune disease, and to recommend appropriate management.
  
  
  METHODS
  An extensive literature review was supplemented with a MEDLINE search. Articles from easily available journals were preferred. These consisted of the most recent basic articles on autoimmunity in relation to chronic urticaria and a selection of previous articles on pathophysiology, which illustrate consistencies with recent evidence. The investigation and management protocol is supported by original and relevant literature.
  
  
  RESULTS
  The histopathology and immunohistology of chronic urticaria and certain clinical studies were a prelude to definitive evidence that most instances of chronic urticaria are autoimmune. Although allergic and other causes are uncommon, these must be sought because identification can lead to cure or specific treatment. Management of the much more common autoimmune urticaria is based on principles derived from the demonstrated pathogenesis and on results of published clinical trials.
  
  
  CONCLUSIONS
  In most instances, chronic urticaria is an autoimmune disease, but uncommon allergic or other causes must be considered.
authors.affiliation: Division of Clinical Immunology, St Michael's Hospital, Toronto.
authors.forename: A
authors.initials: A
authors.lastname: Leznoff
mesh_terms: D000465:Algorithms; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D002908:Chronic Disease; D003663:Decision Trees; D003937:Diagnosis, Differential; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D014581:Urticaria / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*