title: A prospective ten-year follow-up of patients with chronic urticaria.
abstract: BACKGROUND
  Chronic urticaria can be the initial clinical presentation of a number of different diseases. The objective of the present study was to report the associated diseases during a ten-year clinical-laboratory follow-up in patients with an initial diagnosis of chronic spontaneous urticaria (CSU) of unknown cause.
  
  
  METHODS
  A prospective, longitudinal cohort study with a ten-year clinical-laboratory follow-up was conducted. Patients with a history of urticarial plaques of over six weeks presenting as the only clinical symptom were selected. Individuals with other clinical conditions, urticaria of known causes or chronic physical urticaria were excluded. The following tests were initially performed: haemogram, urine type I, stool parasite exam and sedimentation rate. The following exams were ordered during follow-up: PPD; urine culture; serology tests; antithyroid and antinuclear antibodies, rheumatoid factor, lupus anticoagulant; thyroid hormones; serum immunoglobulin; paranasal sinus and thorax radiographs; testing for BK and Helicobacter pylori; and prick tests.
  
  
  RESULTS
  Infections were diagnosed in 29% of patients (syphilis, parasitosis, H. pylori, urinary infection, tuberculosis, hepatitis B and C); autoimmune diseases in 21% (thyroiditis, rheumatoid arthritis and antiphospholipid antibody syndrome); primary immunodeficiencies in 4% (IgA and IgG2 deficiencies); and chronic myeloid leukaemia in 1%. At ten-years of follow-up, the urticaria diagnosis was CSU of unknown cause in 45% of the cases.
  
  
  CONCLUSIONS
  This ten-year clinical-laboratory follow-up of 100 individuals with chronic urticaria as the initial diagnosis revealed the presence of associated diseases in over half of the cases. The most prevalent diseases were infections and autoimmune diseases besides primary immunodeficiencies and blood diseases.
authors.affiliation: Immunology Discipline, Pathological Sciences Department - Santa Casa de Sao Paulo School of Medical Sciences, São Paulo, Brazil; Allergy and Immunodeficiency Section, Pediatric Department - Santa Casa Hospital, São Paulo, Brazil. Electronic address: medpatty@ig.com.br.
authors.forename: P C L
authors.initials: PC
authors.lastname: Dionigi
authors.affiliation: Immunology Discipline, Pathological Sciences Department - Santa Casa de Sao Paulo School of Medical Sciences, São Paulo, Brazil; Allergy and Immunodeficiency Section, Pediatric Department - Santa Casa Hospital, São Paulo, Brazil.
authors.forename: M C S
authors.initials: MC
authors.lastname: Menezes
authors.affiliation: Immunology Discipline, Pathological Sciences Department - Santa Casa de Sao Paulo School of Medical Sciences, São Paulo, Brazil; Allergy and Immunodeficiency Section, Pediatric Department - Santa Casa Hospital, São Paulo, Brazil.
authors.forename: W C N
authors.initials: WC
authors.lastname: Forte
mesh_terms: D000328:Adult; D001327:Autoimmune Diseases / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D002908:Chronic Disease; D003141:Communicable Diseases / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D004406:Dysgammaglobulinemia / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012882:Skin Tests; D014581:Urticaria / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology
keywords: Autoimmune diseases; Chronic myeloid leukaemia; Chronic spontaneous urticaria; Diagnosis; Infectious diseases; Primary immunodeficiency; Urticaria