Crohn's Disease: Key Conditions for Differential Diagnosis

Crohn's disease presents a significant challenge in clinical diagnosis, especially when differentiating it from other gastrointestinal conditions. One of the most difficult diseases to distinguish it from is intestinal tuberculosis. The most common areas affected by Crohn's disease are the terminal ileum and ileocecal region. Although the condition can affect any part of the gastrointestinal tract, these areas are most frequently involved. Interestingly, intestinal tuberculosis also commonly affects the same regions, making differentiation crucial.

1. Intestinal Tuberculosis

Intestinal tuberculosis typically develops in areas rich in lymphoid tissue, which includes the ileocecal junction and small intestine. This overlap in affected areas necessitates careful differentiation between the two conditions. Patients with intestinal tuberculosis often have a history of pulmonary tuberculosis, exposure to tuberculosis in the household, or evidence of pulmonary lesions. Tuberculosis testing is usually positive in such cases, and histopathological examination reveals caseating granulomas. In contrast, Crohn's disease is characterized by non-caseating granulomas, which is a key distinguishing feature.

2. Behçet's Disease

Another condition that must be differentiated from Crohn's disease is Behçet's disease. This is a systemic disorder involving vascular inflammation and can lead to ulcerations in the gastrointestinal tract, particularly in the ileocecal region. However, Behçet's disease is not limited to the intestines. It often presents with recurrent oral ulcers and may also cause ulcers in the anal region. These extraintestinal manifestations are important indicators that help clinicians distinguish it from Crohn's disease.

3. Intestinal Lymphoma

Intestinal lymphoma is another condition that shares clinical and radiological features with Crohn's disease. Both may present with intestinal wall thickening, ulcers, and abdominal symptoms. However, lymphoma tends to occur more frequently in older adults and may present with systemic symptoms like weight loss and night sweats. Histopathological evaluation is essential for accurate diagnosis and differentiation.

4. Infectious and Ischemic Bowel Diseases

Infectious causes such as amoebiasis, schistosomiasis, fungal infections, and viral enteritis must also be considered when diagnosing Crohn's disease. These infections can mimic the symptoms and endoscopic findings of inflammatory bowel disease. Additionally, ischemic colitis—caused by reduced blood flow to the intestines—can resemble Crohn's disease in presentation. Accurate diagnosis often requires a combination of clinical evaluation, imaging, laboratory tests, and histological analysis.