DISCUSSION
We report two observations of disseminated TB with digestive damage revealed following an inappropriate prescription of corticosteroid therapy in the context of inflammatory ileo-colitis. In Madagascar, it is still very difficult to differentiate intestinal tuberculosis from Crohn’s disease due to lack of technical facilities and insufficient resources of patients. We retain that intestinal tuberculosis should be systematically mentioned first in endemic countries in the event of inflammatory ileo-colitis. Prescribing immunosuppressants is dangerous in this situation, and should only be prescribed after formal elimination of tuberculosis.
ITB is an extra-pulmonary form of tuberculosis, secondary to hematogenous dissemination, or by local extension following peritoneal involvement or endogenously from swallowed bacilliferous sputum in patients with active pulmonary forms.1, 8, 9 Its frequency is estimated at 3 to 5%.1, 2 Abdominal tuberculosis mainly affects young adults with a peak frequency between 21 and 45 years. The predominance of women has been observed in countries endemic to TB. Tuberculous involvement mainly concerns the ileum, the ileocecal junction and then the colon.1, 8-10 CD remains a very rare disease in Africa, especially in sub-Saharan Africa.3, 4 In order of frequency, ITB should be mentioned before CD in an endemic TB zone in the event of inflammatory ileo-colitis.3
Confusion between ITB and CD poses a real diagnostic problem and a very high diagnostic error rate ranging from 50 to 70%, causing inadequate prescription of corticosteroid therapy. This similarity concerns all aspects of these diseases, clinico-radiological, endoscopic and even histopathological.1, 2, 3 Clinical, radiological and endoscopic criteria have been established by certain authors but they are disappointing.1, 3 The presence of ascites remains more frequent in the course of TB and has been judged as a more specific clinical criterion in favor of the latter.11
Endoscopic differentiation in colonoscopy between ITB and CD is difficult since both diseases can present with mucosal ulcers, apthous ulcers and pseudo-polyps.12, 13 In the literature, caseous necrosis and the presence of acid-alcohol-resistant bacilli to Ziehl and Nielsen staining allow a definite diagnosis of TB to be established, but are seen in 22% and 26-36% respectively.1, 8, 14, 15 Therefore, currently available diagnostic confirmation methods have limitations. In our observations, the absence of ascites, gigantocellular granuloma, caseous necrosis during biopsy with absence of acid-fast bacilli at the start misled us and prompted us to erroneously prescribe corticosteroid therapy. This inadequate prescription of corticosteroid therapy led to an explosion of TB symptoms. Demory et al had reported a deceptive case of ITB mimicking CD, leading to inappropriate prescription of corticosteroid therapy, favoring tuberculous explosion with tight stenosis of terminal ileum.7 Gargouri etal reported a similar situation where corticosteroid therapy exacerbated TB disease.6 In our observations, corticosteroid therapy led to an explosion and dissemination of TB and allowed us to correct our initial diagnosis. Therefore, it is imperative to differentiate these two diseases since the immunosuppressants often used in CD, can lead to an explosion of TB symptoms or even complications which can be fatal.1, 5, 6, 7Tuberculous ileo-colitis should be ruled out before initiating corticosteroid therapy to avoid possible tuberculous complications.1, 6, 7 In our observations, corticosteroid therapy aroused initially inactive pulmonary TB, with secondary appearance of a typical pulmonary radiological image and a positive bascilloscopy. In the literature, this pulmonary involvement can be seen in 9.87% to 30% of cases of ITB.8-10 The response to TB treatment confirms diagnosis if in doubt.6-8 Some authors have even proposed a therapeutic algorithm for inflammatory ileo-colitis, to make our daily exercise more practical (Figure 5).3
The management of ITB must be medical and conservative as far as possible, because of the clinical decline of patients (anemia, malnutrition and immunosuppression).16 The TB treatment recommended by the majority of guideline in adults is a daily treatment in two phases spread over two months of initial quadruple therapy (Isoniazid, Rifampicin, Pyrazinamide and Ethambutol) followed by 4 to 7 months of dual therapy (Isoniazid and Rifampicin) in maintenance.1, 16-18 The effectiveness of medical treatment is judged on the disappearance of fever, ascites and weight gain in 4-6 weeks.16-19 Surgery should be reserved for complicated forms.20 Our two patients had received a 6-months medical treatment with satisfactory outcome and were declared cured at the end of treatment.