title: Review article: the diagnosis and management of Crohn's disease in populations with high-risk rates for tuberculosis.
abstract: BACKGROUND
  Distinguishing Crohn's disease from intestinal tuberculosis in endemic areas is challenging as both conditions have overlapping clinical, radiological, endoscopic and histological characteristics. Furthermore, high rates of latent tuberculosis confer a considerable risk of reactivation once therapy for established Crohn's disease is started.
  
  
  OBJECTIVE
  To review current strategies in differentiating these two conditions, and in managing Crohn's disease, in populations with high rates of tuberculosis.
  
  
  METHODS
  Literature review and clinical experience.
  
  
  RESULTS
  While various clinical, radiological, endoscopic and histological parameters may aid in differentiating Crohn's disease from intestinal tuberculosis, these remain imperfect and as treatment options differ misdiagnosis has grave consequences. We propose a diagnostic algorithm, based on currently available evidence and experience, to aid in this dilemma. We also discuss approaches to the management of Crohn's disease, including agents targeting tumour necrosis factor-alpha, in patients at risk of developing tuberculosis.
  
  
  CONCLUSIONS
  A diagnosis of Crohn's disease in individuals at risk for tuberculosis should only be made after careful interpretation of clinical signs, abdominal imaging and systematic endoscopic and histological assessment. Newer techniques for the diagnosis of latent tuberculosis still need to be validated in this environment, and guidelines on the treatment of latent tuberculosis in this setting require clarification.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa. epstein@curie.uct.ac.za
authors.forename: D
authors.initials: D
authors.lastname: Epstein
authors.forename: G
authors.initials: G
authors.lastname: Watermeyer
authors.forename: R
authors.initials: R
authors.lastname: Kirsch
mesh_terms: D000465:Algorithms; D000995:Antitubercular Agents / Q000627:therapeutic use*; D003424:Crohn Disease / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D003937:Diagnosis, Differential; D019353:Endemic Diseases; D016099:Endoscopy, Gastrointestinal; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D012307:Risk Factors; D014385:Tuberculosis, Gastrointestinal / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D000995:Antitubercular Agents; D007155:Immunologic Factors; D014409:Tumor Necrosis Factor-alpha