Crohn Disease in Adults

Background

• Crohn disease (CD) is a chronic, inflammatory, multisystem disorder characterized by patchy, asymmetric, transmural, and occasionally granulomatous inflammation. It mainly affects the gastrointestinal tract, most commonly the terminal ileum and/or colon.
• CD incidence is highest between age 10 and 30 years, but CD can present at any age.
• The exact cause of CD is unknown, but it likely results from a combination of environmental factors, genetic susceptibility, gut microbiome dysbiosis, and aberrant innate and adaptive immune responses.
• Risk factors for CD include family history of autoimmune or inflammatory bowel disease, recent use of antibiotics, cigarette smoking, and presence of known associated autoimmune and inflammatory conditions.
• Patients who have had CD for > 8-10 years have increased risk of colorectal cancer. CD is also associated with an increased risk of small bowel cancers.

Evaluation

• Crohn disease (CD) commonly presents with one or more of the following:
  • abdominal pain or cramping
  • diarrhea of at least 4 weeks duration with or without blood and/or mucus
  • constitutional symptoms of weight loss, fatigue, and fever
• Less commonly, patients may present with urgent symptoms of severe CD such as acute abdomen, bowel obstruction or ileus, or sepsis.
• Ask about:
  • presence of known associated autoimmune and inflammatory conditions
  • extraintestinal involvement, which may be present in up to 40% of patients, including psoriasis or other skin conditions, uveitis, episcleritis, oral aphthous ulcers, spondyloarthritis, and peripheral arthritis
• Physical exam should include general condition, body weight, abdominal and perineum/perianal exams (including digital rectal exam whenever possible), and assessment for extraintestinal involvement.
• Initial testing may include hematologic and chemistry profiles:
  • Anemia and elevated platelets reported to be most common abnormalities on complete blood count in patients with CD.
  • In patients at risk of malnutrition, assessment for nutritional deficiencies may include measurement of iron stores, vitamins B12 and D, folate, potassium, calcium, magnesium, and phosphate as well as considering minerals such as zinc and selenium.
  • Consider measuring inflammatory markers, such as C-reactive protein and/or fecal calprotectin, which are nonspecific but may provide additional support for assessment of severity and/or establishing the diagnosis.
• Rule out other causes of chronic diarrhea, such as infection (consider bacterial, Giardia and even other parasites, viral, or fungal testing in the right settings), and ulcerative or drug-induced colitis.
• Confirm the diagnosis endoscopic evaluation and biopsy. Histologic findings of lymphogranulocytic infiltrates, crypt distortion, granulomas, and transmural inflammation all support the diagnosis. Small bowel deep endoscopic methods and imaging can both provide information about small intestinal involvement, depending on local resources.
• Imaging, using magnetic resonance imaging, computed tomography, or ultrasound, is a useful adjunct to endoscopy and can help evaluate both luminal and extraluminal disease. Typical radiologic findings include discontinuous transmural asymmetric lesions, cobblestoning, deep ulcers and/or fissures.

Management

General Management Strategies

• General approach to management for Crohn disease
  • Correct any nutritional deficiencies and electrolyte disorders in patients with Crohn disease.
  • Advise avoidance or cessation of cigarette smoking, which exacerbates disease activity (Strong recommendation).
  • Assess and manage stress, depression, and anxiety as part of the comprehensive care plan of Crohn disease (Strong recommendation). Consider offering cognitive behavioral therapy, hypnotherapy, or mindfulness meditation to interested patients, particularly those with psychological symptoms (Weak recommendation).
  • Routinely ask about medication adherence. Offer a variety of means to facilitate adherence, including regimen simplification, reminder aids, and patient education Strong recommendation).
  • There is limited evidence for dietary interventions as a primary management strategy in adults with Crohn disease, but dietary modifications may be considered as adjunctive to other therapies aimed to induce remission. See also:
    • Nutritional Therapy for Acute Disease in Induction of Remission in Crohn Disease in Adults
    • Dietary Maintenance in Maintenance Therapy for Crohn Disease in Adults
  • See also the following content in Maintenance Therapy for Crohn Disease in Adults:
    • Mental Health Maintenance
    • Smoking Cessation
• Because most patients with Crohn disease will receive immunosuppressive treatment at some point in their lives, make efforts to prevent opportunistic infection.
  • Ensure vaccination history is up to date for all patients with Crohn disease (Strong recommendation).
  • Screening for infections, including tuberculosis and hepatitis B, is suggested at the time of Crohn diagnosis (Weak recommendation) and recommended before initiating any immunomodulatory or biological therapy (Strong recommendation).
  • see Prevention of Opportunistic Infection in Induction of Remission in Crohn Disease in Adults
• Surveillance and monitoring
  • Perform surveillance with ileocolonoscopy to screen for colorectal neoplasia in patients with Crohn disease and colon involvement 8 years after symptom onset (Strong recommendation).
  • Screening is recommended for adults with Crohn disease, including but not limited to osteoporosis, both melanoma and nonmelanoma squamous cell skin cancer (particularly if receiving immunomodulators such as 6-mercaptopurine or azathioprine) (Strong recommendation), and cervical cancer in women receiving immunosuppressive therapy (Weak recommendation).
  • see Preventive Care for Adults with Crohn Disease in Maintenance Therapy for Crohn Disease in Adults

Medical and Surgical Management

• Clinical symptoms should not be the sole guide for treatment decisions. Consider "treating to target" (combined clinical and endoscopic remission) to reduce the risk of future relapse or complications.
• Severity and risk assessment typically includes clinical symptoms, Crohn Disease Activity Index (CDAI) score, Simple Endoscopic Score for Crohn's Disease (SES-CD), and personal prognostic risk factors. See also:
  • CDAI DynaMed Calculator
  • Typical features associated with grades of severity:
    • Mild-to-moderate disease - usually corresponds to CDAI score 150-220 and is characterized by the ability to ambulate and tolerate oral feedings without significant weight loss, abdominal tenderness, dehydration, obstruction, or systemic toxicity, as well as absence of endoscopic ulcers > 2 cm.
    • Moderate-to-severe disease - usually corresponds to CDAI score 220-450 and is characterized by prominent symptoms of fever, significant weight loss, abdominal pain or tenderness, intermittent nausea or vomiting (without obstructive findings), anemia, and moderate-to-severe endoscopic activity.
    • Severe/fulminant disease - usually corresponds to CDAI score > 450 and is characterized by high fevers, persistent vomiting, intestinal obstruction, significant peritoneal signs, cachexia, and evidence of abscess.
• Consider a "top-down" approach for patients with poor prognostic factors, severe/extensive disease, or complicated disease, and a "step-up" approach for patients with low risk for disease progression (Weak recommendation).
  • Top-down therapy entails early, aggressive therapy with biologics with or without immunosuppressants.
  • Step-up therapy entails initiating therapy with systemic corticosteroids and reserving biologic therapies for patients who become steroid-dependent or who fail first- or second-line agents.
• Severe complications, perianal abscess, or fistula should prompt referral to surgical consultation.
• Induction of remission in Crohn disease:
  • Treatment recommendations for Crohn disease are guided by disease severity and risk status of individual patients.
  • Medication approaches vary by severity of disease but include corticosteroids, thiopurines, methotrexate, tumor necrosis factor inhibitors, or other biologics.
  • Monitor for adverse events closely throughout the administration of acute therapy. Evaluate for response within several weeks of initiation. Generally, acute treatment should be continued until symptomatic remission or there is a failure to continually improve.
• Maintenance therapy for quiescent Crohn disease:
  • Recommended maintenance regimens vary by the induction regimen used. Options include thiopurines, methotrexate, tumor necrosis factor inhibitors, and/or other biologics.
  • Chronic corticosteroid use should be avoided.
  • Follow-up may include periodic assessment of inflammatory markers, blood counts, liver and renal function, nutritional status, and consideration of bone mineral density and/or drug levels.
  • For mild symptoms in patients with low risk of progression, offering any of the following combined with careful observation for inadequate relief, worsening inflammation, or disease progression are recommended: antidiarrheals, anticholinergics, or dietary manipulation (Strong recommendation).
  • For functional pain, consider antispasmodics, neuropathic-directed agents, and antidepressants. Avoid long-term opioid use.
• Surgical management of Crohn disease:
  • Indications for surgery in Crohn disease include medically refractory disease and enteric complications. Surgical indications supported in guidelines include
    • failed medical therapy
    • complex perianal fistula, with or without abscess
    • perianal abscess
    • intra-abdominal abscess
    • acute severe colitis (also known as fulminant disease)
    • stricture with small bowel obstruction
    • abdomino-pelvic sepsis
    • penetrating disease/perforation
    • dysplasia or cancer
    • patient preference to discontinue drug therapy for localized disease
    • intractable hemorrhage
  • The goal of surgery should include preserving bowel length to avoid short bowel syndrome or intestinal failure. Resection of diseased portion of small intestine is the most common surgery for Crohn disease.
  • For fibrostenotic stricture resection or strictureplasty are recommended after failure of medical therapy and/or endoscopic dilation.
  • Postoperative endoscopic follow-up and monitoring is suggested at 6-12 months, particularly in patients not receiving maintenance medication due to lower risk of recurrence (Weak recommendation).
  • The approach to medication management postoperatively depends on individual risk for recurrence.
    • Consider no treatment for 6 months after surgery if low risk for recurrence. One common strategy is to perform follow up ileocolonoscopy at 6-12 months and add anti-TNF therapy if there is evidence of inflammation.
    • Consider thiopurines with or without metronidazole if penetrating disease (but no smoking, prior surgical resection history, or prior medication). Perform follow-up colonoscopy at 6 months and if there is evidence of recurrence at colonoscopy, add anti-TNF therapy.
    • Starting anti-TNF agents within 4 weeks of surgery in patients at high risk of recurrence (such as people who smoke or those had a prior resection within 10 years of current surgery) is suggested to prevent postoperative Crohn disease recurrence (Weak recommendation).