From the Guidelines
The initial workup for suspected Crohn's disease should include a comprehensive history and physical examination, followed by laboratory tests and imaging studies, with a combination of CT enterography and ileocolonoscopy being the diagnostic algorithm of choice at initial presentation. This approach is based on the most recent evidence from the American College of Radiology, which recommends CT enterography and ileocolonoscopy as the initial diagnostic tests for suspected Crohn's disease 1.
Initial Evaluation
The initial evaluation should include:
- Comprehensive history and physical examination
- Laboratory tests such as:
- Complete blood count
- C-reactive protein
- Erythrocyte sedimentation rate
- Comprehensive metabolic panel
- Fecal calprotectin
- Imaging studies, typically starting with abdominal ultrasound or CT scan, followed by endoscopic evaluation with colonoscopy and upper endoscopy with biopsies
Diagnostic Algorithm
The diagnostic algorithm of choice at initial presentation is a combination of CT enterography and ileocolonoscopy, as recommended by the American College of Radiology 1. Ileocolonoscopy with biopsy is established as the first-line investigation for suspected Crohn’s disease, and CT enterography allows for assessment of the entire small bowel, including the distal ileum, and is helpful in establishing a CD diagnosis in cases in which the terminal ileum and colon are not involved or when intramural disease is predominant 1.
Treatment
Treatment for Crohn's disease should be based on the severity of the disease and the patient's response to initial therapy. The British Society of Gastroenterology recommends the use of sulfasalazine to induce complete remission in patients with mild Crohn’s disease limited to the colon, while the Canadian Association of Gastroenterology recommends the use of oral budesonide beginning at 9 mg/day as first-line therapy to induce complete remission in patients with mild to moderate ileal and/or right colonic Crohn’s disease 1. For moderate to severe disease or steroid-dependent cases, biologic agents such as infliximab or adalimumab are recommended 1.
Additional Considerations
Additional considerations in the management of Crohn's disease include:
- Nutritional support
- Vitamin D and B12 supplementation
- Iron replacement
- Antibiotics like metronidazole or ciprofloxacin for perianal disease or bacterial overgrowth
- Immunomodulators like azathioprine or methotrexate for maintenance therapy
- Regular follow-up and monitoring to adjust treatment as needed.
From the FDA Drug Label
The FDA drug label does not answer the question about the initial workup for a patient presenting with suspected Crohn's disease. The provided drug labels for adalimumab (2) and infliximab (3) discuss the treatment of Crohn's disease but do not provide information on the initial workup or diagnosis of the condition. Key points to consider in the diagnosis of Crohn's disease include:
- Clinical presentation
- Laboratory tests
- Endoscopic evaluation
- Imaging studies However, the FDA drug labels provided do not directly address these points, and therefore, no conclusion can be drawn from the labels regarding the initial workup for suspected Crohn's disease.
From the Research
Initial Workup for Suspected Crohn's Disease
- The initial workup for a patient presenting with suspected Crohn's disease includes a physical examination to identify unstable patients requiring immediate care, an anorectal examination, and a search for extraintestinal complications 4.
- Laboratory evaluation is used to identify inflammation and screen for alternative diagnoses, with measurement of fecal calprotectin having value in ruling out disease in adults and children 4.
- Endoscopy and cross-sectional imaging, such as MR enterography (MRE), are used to confirm the diagnosis and determine the extent of disease 5, 4, 6, 7.
Diagnostic Imaging
- MRE has been shown to correlate highly with colonoscopy and histology for both distal ileal and colonic Crohn's disease, with a sensitivity of 85% and specificity of 80% 5.
- MRE is also effective in detecting small bowel activity in Crohn's disease patients, with a sensitivity of 90% and specificity of 89% 7.
- Intestinal US is also a useful modality in the diagnosis and monitoring of Crohn's disease, particularly in assessing disease activity and treatment response 6.
Treatment
- Treatment decisions are guided by disease severity and risk of poor outcomes, with patients commonly receiving corticosteroids to treat symptom flare-ups 4.
- Patients with higher-risk disease are given biologics, with or without immunomodulators, to induce and maintain remission 4, 8.
- Enteral nutrition is an option for induction therapy in children with Crohn's disease 4.
- Patients with Crohn's disease should be counseled on smoking avoidance or cessation, and maximizing prevention measures is essential in caring for these patients 4.
Predicting Surgical Intervention
- The presence of stenosis or intra-abdominal fistulae at MRI correlates with a higher risk of surgery, while months under immunomodulators and/or antitumor necrosis factor (anti-TNF) therapy during follow-up decreases this risk 8.
- Perianal disease, stenosis, and/or intra-abdominal fistulae at MRI independently predict an increased risk of resection surgery in patients with Crohn's disease 8.