distinguishing features of ulcerative colitis vs Crohn's disease

Differential diagnosis

• lesions
  • UC* crypt abscesses & superficial inflammation from rectum through colon (involves rectum, no skipped areas)
    • disorder of the colonic mucosa; lesion does NOT extend transmurally (in contrast to Crohn's disease)
  • CD* linear ulcerations with skipped (normal) areas involving entire GI tract; rectum not necessarily involved
    • affects the entire wall of the GI tract (transmural)
    • fistulas & strictures are frequent complications
    • abdominal abscesses & perirectal abscesses are also common
• signs/symptoms
  • UC* diarrhea prominant, hematochezia, weight loss, fever
  • CD* abdominal pain prominant, diarrhea, inflammatory masses, fever, weight loss
• laboratory
  • UC* anti-Saccharomyces cerevisiae antibodies (ASCA) 10%; p-ANCA 75%
  • CD* anti-Saccharomyces cerevisiae antibodies (ASCA) 60%; p-ANCA 10%
• smoking
  • UC* alleviates symptoms
  • CD* risk factor for disease

* UC = ulcerative colitis; CD = Crohn's disease