title: Clinical characteristics of collagenous and lymphocytic colitis.
abstract: BACKGROUND
  Microscopic colitides (MC), collagenous colitis (CC) and lymphocytic colitis (LC) share clinical features, but their mutual relationship is unclear, and clinical comparative studies are rare. We aimed to examine the clinical features in CC and LC by focusing on concomitant diseases.
  
  
  METHODS
  Patients with MC (30 with CC, 54 with LC) were identified in the pathology databases and by reviewing biopsies. Controls included 84 age- and sex-matched persons. The clinical data collected from patient records were prospectively completed by interviews.
  
  
  RESULTS
  The female:male ratio was 2:1 in CC and 5.75:1 in LC. Mean age at diagnosis was 53 in CC and 55.4 years in LC. There were no differences in the pattern of symptoms. Concomitant autoimmune diseases were more common in CC (53.3%) than in LC (25.9%; P = 0.017). Celiac disease was common in both CC (20%) and LC (14.8%). Bronchial asthma was associated with LC (25.9%), but not with CC (6.7%; P = 0.042). Colon diverticulosis was rare in MC (16%) compared with the controls (39%; P = 0.001). Hypolactasia was common in MC (45%; 76% in CC, 54% in LC) compared to its prevalence in the Finnish general population (17%).
  
  
  CONCLUSIONS
  CC and LC are largely similar clinically, but the differences in the occurrence of autoimmune conditions and bronchial asthma suggest that they differ in immunopathogenesis. MC is associated with reduced lactose tolerance and shows a negative association with diverticular disease, possibly related to the small intestinal pathology and abnormal stool consistency.
authors.affiliation: Department of Internal Medicine, University of Oulu, OYS, PO Box 20, FIN-90029 Oulu, Finland. ritva.m.koskela@ppshp.fi
authors.forename: R M
authors.initials: RM
authors.lastname: Koskela
authors.forename: S E
authors.initials: SE
authors.lastname: Niemelä
authors.forename: T J
authors.initials: TJ
authors.lastname: Karttunen
authors.forename: J K
authors.initials: JK
authors.lastname: Lehtola
mesh_terms: D017677:Age Distribution; D001707:Biopsy, Needle; D001774:Blood Chemical Analysis; D016022:Case-Control Studies; D046729:Colitis, Collagenous / Q000453:epidemiology* / Q000473:pathology*; D046730:Colitis, Lymphocytic / Q000453:epidemiology* / Q000473:pathology*; D003113:Colonoscopy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008297:Male; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D018709:Statistics, Nonparametric