What are the clinical features of Crohn's disease?

Clinical Features of Crohn's Disease

Crohn's disease is a chronic inflammatory disease that can affect the entire gastrointestinal tract, primarily presenting with abdominal pain, diarrhea, and weight loss, with the terminal ileum and colon being the most commonly affected sites. 1

Common Clinical Presentations

• Gastrointestinal Symptoms:

  • Abdominal pain (typically colicky in nature) 1
  • Diarrhea (may be bloody or non-bloody) 1, 2
  • Weight loss 1, 2
  • Anorexia and fatigue 3, 2
  • Rectal bleeding 4
  • Fever 2

• Disease Distribution:

  • Can affect any part of the gastrointestinal tract from mouth to anus 1
  • Terminal ileum and colon are most commonly affected sites 1
  • Small bowel alone is affected in approximately one-third of patients 1
  • Colon alone is affected in a higher percentage of patients 1
  • Combined small bowel and colonic involvement occurs in less than one-third of patients 1
  • Perianal disease is common 1, 2

• Disease Behavior:

  • Transmural inflammation (affects all layers of bowel wall) 1, 5
  • Three main phenotypes: inflammatory, stricturing, and penetrating 2
  • Up to 50% develop stricturing or fistulizing disease over time 5
  • Skip lesions (areas of inflammation interspersed with normal bowel) 2, 5

Extraintestinal Manifestations

• Present in up to half of patients with Crohn's disease 5
• Common manifestations include:
  • Inflammatory arthropathies/arthritis 6, 5
  • Erythema nodosum 1, 5
  • Anterior uveitis/scleritis 3, 6
  • Osteoporosis 3, 6
  • Nephrolithiasis and cholelithiasis 6
  • Hepatic complications 3
  • Hematological alterations 3

Disease Course and Patterns

• Characterized by periods of exacerbation and remission 1
• Approximately 50% of patients experience a relapse in any given year 1
• 20-30% of patients with pancolitis eventually require colectomy 1
• At least 50% require surgical treatment within 10 years of diagnosis 1
• 70-80% will require surgery within their lifetime 1
• Surgery is not curative in Crohn's disease 1, 2

Diagnostic Findings

• Laboratory Findings:

  • Elevated inflammatory markers (C-reactive protein, erythrocyte sedimentation rate) 4, 6
  • Fecal calprotectin (high sensitivity and specificity for distinguishing IBD from IBS) 7, 4
  • Fecal lactoferrin (helps differentiate IBD from functional disorders) 7
  • Anemia 6
  • Hypoalbuminemia 1
  • Vitamin B12, folate, and vitamin D deficiencies 6

• Diagnostic Testing:

  • Ileocolonoscopy with biopsy is the primary diagnostic tool 1, 6
  • Capsule endoscopy for suspected small bowel involvement 1
  • Cross-sectional imaging (CT enterography, MR enterography) 1, 6
  • Stool cultures to rule out enteric infections 1, 7
  • Clostridium difficile testing (important in all flares) 1, 7

Special Considerations

• Night sweats may suggest intestinal tuberculosis, which can mimic Crohn's disease 8
• Differentiating between intestinal tuberculosis and Crohn's disease can be challenging in endemic areas 1
• Features suggesting tuberculosis include night sweats, concomitant pulmonary TB, positive tuberculin skin test, abdominal lymphadenopathy, and transverse ulcers 1
• Features suggesting Crohn's disease include hematochezia, sigmoid colon involvement, skip lesions, and aphthous ulceration 1
• Cytomegalovirus testing should be considered in patients with moderate to severe colitis, particularly those with steroid-refractory disease 1, 7

Impact on Quality of Life

• Significant disability with only 75% of patients fully capable of work in the year after diagnosis 1
• 15% of patients unable to work after 5-10 years of disease 1
• High incidence of psychological morbidity in both children and adults 1
• Concerns about body image and living with chronic illness 1