title: Association between chronic urticaria and thyroid autoimmunity: a prospective study involving 99 patients.
abstract: BACKGROUND
  The association between chronic urticaria and thyroid autoimmunity has been a subject of debate. However, this link was suggested in studies searching thyroid microsomal antibodies (TMA), which are less sensitive and less specific than anti-thyroperoxidase antibodies, moreover these studies did not measure anti-TSH receptor antibodies, nor did they use a control group. As a consequence, the results of these studies are difficult to interpret.
  
  
  OBJECTIVE
  The aim of this study was to determine whether chronic urticaria is statistically associated with thyroid autoimmunity.
  
  
  METHODS
  In a prospective case-control study, we compared the frequency of thyroid autoantibodies in 45 patients with chronic urticaria and in 30 healthy adult volunteers; we also compared the frequency of chronic urticaria in 32 patients with thyroid diseases with thyroid autoantibodies and in 22 patients with thyroid diseases without thyroid autoantibodies. Thyroid autoantibodies and thyroid hormones were measured in all the subjects; antinuclear antibodies, rheumatoid factors, complement, IgE were assessed and routine laboratory tests were done in patients with chronic urticaria. Fisher's exact statistics were used to test our hypothesis.
  
  
  RESULTS
  The frequency of thyroid autoantibodies was significantly higher in patients with chronic urticaria than in healthy controls (26.7%/3.3%; p < 0.01). All the patients with thyroid autoantibodies had thyroid hormone concentrations within the normal limits. The frequency of chronic urticaria was not significantly different (12.5%/9.1%; p = 0.7) in patients with thyroid diseases with or without thyroid antibodies. The rest of the biological investigations revealed only 1 patient with connective tissue disease.
  
  
  CONCLUSIONS
  This study shows a significant association between chronic urticaria and thyroid autoimmunity, and that tests to detect thyroid autoantibodies are relevant in patients with chronic urticaria, whereas extensive laboratory tests are not.
authors.affiliation: Department of Dermatology, University Hospital, Caen, France. laurence.verneuil@laposte.net
authors.forename: L
authors.initials: L
authors.lastname: Verneuil
authors.forename: C
authors.initials: C
authors.lastname: Leconte
authors.forename: J J
authors.initials: JJ
authors.lastname: Ballet
authors.forename: C
authors.initials: C
authors.lastname: Coffin
authors.forename: D
authors.initials: D
authors.lastname: Laroche
authors.forename: J P
authors.initials: JP
authors.lastname: Izard
authors.forename: Y
authors.initials: Y
authors.lastname: Reznik
authors.forename: D
authors.initials: D
authors.lastname: Leroy
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D013959:Thyroid Diseases / Q000453:epidemiology* / Q000276:immunology; D013967:Thyroiditis, Autoimmune / Q000453:epidemiology* / Q000276:immunology; D014581:Urticaria / Q000453:epidemiology* / Q000276:immunology*
chemical_list: D001323:Autoantibodies; C056626:thyroid microsomal antibodies