Clinical Features of Crohn's Disease
Crohn's disease is a chronic inflammatory disease that primarily affects the gastrointestinal tract, presenting with abdominal pain, diarrhea, weight loss, and can be associated with considerable debility due to its long-term course of exacerbations and remissions. 1
Primary Gastrointestinal Manifestations
- Anatomical Distribution: Can affect the entire gastrointestinal tract from mouth to anus, with the terminal ileum and colon being the most commonly affected sites 1
- Abdominal Pain: Typically colicky in nature, a cardinal symptom present in most patients 1, 2
- Diarrhea: Chronic diarrhea is a hallmark feature, may be bloody or non-bloody 2, 3
- Weight Loss: Significant weight loss occurs due to malabsorption and reduced intake 2, 3
- Perianal Disease: Fistulas, abscesses, and perianal involvement occur in up to a third of patients 1, 3
- Intestinal Obstruction: May develop due to strictures from progressive structural damage 1, 2
- Fistula Formation: Penetrating disease can lead to development of internal or external fistulas 3
Systemic Manifestations
- Systemic Symptoms: Malaise, anorexia, and fever are more common in Crohn's disease than in ulcerative colitis 1, 2
- Fatigue: Common complaint that significantly impacts quality of life 2, 4
- Growth Impairment: In pediatric patients, failure to thrive, growth impairment, and delayed puberty may be present 4
Extraintestinal Manifestations
- Musculoskeletal: Inflammatory arthropathies, arthritis, and osteoporosis 2, 5
- Cutaneous: Erythema nodosum and other skin manifestations 2, 4
- Ocular: Scleritis, uveitis, and other inflammatory eye conditions 5, 4
- Hepatobiliary: Cholelithiasis and other liver complications 5
- Hematological: Anemia is common due to chronic inflammation, blood loss, or malabsorption 5, 3
Disease Patterns and Classification
- Disease Phenotypes: Three main phenotypes exist: inflammatory, stricturing, and penetrating 3
- Disease Course: Characterized by exacerbations and remissions, with 50% of patients experiencing a relapse in any given year 1
- Disease Severity: Can range from mild to severe, with severe disease potentially being life-threatening 1
Laboratory Findings
- Inflammatory Markers: Elevated C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fecal calprotectin are common during active disease 6, 5
- Nutritional Deficiencies: Low levels of vitamin B12, folate, albumin, prealbumin, and vitamin D may indicate malnutrition 5
Diagnostic Considerations
- Stool Studies: Essential to rule out enteric infections, particularly Clostridioides difficile, which can mimic or exacerbate disease 1, 6
- Differential Diagnosis: Important to distinguish from intestinal tuberculosis, particularly in endemic areas, as clinical features may be similar 1
- Night Sweats: When present with abdominal symptoms, should raise suspicion for intestinal tuberculosis 1, 7
Impact on Quality of Life
- Work Capacity: About 75% of patients are fully capable of work in the year after diagnosis, but 15% may be unable to work after 5-10 years 1
- Psychological Impact: High incidence of psychological morbidity in both children and adults with Crohn's disease 1
Complications
- Surgical Intervention: At least 50% of patients require surgical treatment in the first 10 years, and approximately 70-80% will require surgery within their lifetime 1, 3
- Mortality Risk: Slightly higher mortality than the normal population, greatest in the first 2 years after diagnosis or in those with upper gastrointestinal disease 1
- Colorectal Cancer: Increased risk of colorectal cancer in patients with Crohn's colitis 1
Understanding these clinical features is essential for early diagnosis, appropriate management, and monitoring of disease progression in patients with Crohn's disease.