Distinguishing Crohn's disease from intestinal tuberculosis--a prospective study

Distinguishing Crohn's disease (CD) from intestinal tuberculosis (ITB) is clinically challenging but important for prognostication and patient management.

Patients with diagnosis of CD and ITB were prospectively enrolled in the study from January 2006 to October 2007. The patients were followed up for further 15 months to ascertain that the diagnosis had not changed. Clinical, laboratory, serological [IgG anti Saccharomyces cerevisiae antibody (ASCA)], endoscopic and histologic features were compared between the ITB and CD patients. The ASCA titers were estimated in 100 healthy controls. Patients were diagnosed as ASCA positive when their ASCA titers were three standard deviations above mean of controls.

Thirty patients with CD (age 33.9 + 15.2 years, 70% males) and thirty with ITB (age 35.1 + 12.2years, 53.3% males) were included in the study. Features commoner in CD were longer duration of symptoms (p < 0.001), blood mixed stool (p = 0.006), presence of longitudinal ulcers (p = 0.005) and skip lesions (p = 0.008) on colonoscopy and more number of colonic segments involved (p = 0.004). Anorexia was commoner in ITB patients (p = 0.008). Positive ASCA was commoner in CD (30%) than ITB (10%) but did not reach statistical significance (p = 0.1).

A combined evaluation of clinical features, endoscopy, histology and response to treatment is the key to differentiate between CD and ITB.