Crohn disease

• CT:
  • "double halo" (50%): edematous mucosa/thickened soft tissue
  • "creeping fat" (40%): mesenteric infiltration
• US:
  • thickened bowel wall (65%): about 8mm
  • inflammatory mass (14%), abscess (4%), distended fluid filled loops (12%)

• Complications: fistula (33%), intramural sinus tracts, abscess, perforations (rare), toxic megacolon, SBO (15%), hydronephrosis (usually right sided), adenocarcinoma in ileum/colon

• DDx:
  • Yersinia: in TI, resolution in 3-4 months
  • TB (more severe involvement of cecum)
  • segmental infarction (acute onset, elderly patient)
  • radiation ileitis
  • lymphoma
  • carcinoid
  • eosinophilic gastoenteritis
  • potassium stricture

see:

• sites
• phases
• extraintestinal manifestations

More info: Crohn disease [OMIM]

© 2002, C.E. Kahn, Jr.
2002-04-18