Pseudomembranous Colitis
Differential Diagnosis
| Chemical / Iatrogenic Colitis |
Antibiotic-associated Pseudomembranous Colitis |
| Diffuse necrosis and sloughing of superficial mucosa |
Frequently patchy involvement of 2-10 crypts with normal surrounding crypts |
| Mucosal microthrombi and hemorrhage |
Not associated with microthrombi or hemorrhage |
| History of endoscopy or introduction of foreign substance |
History of antibiotic therapy |
Both may form a pseudomembrane
| Pseudomembranous Colitis |
Enterohemorrhagic E coli Colitis |
| Endoscopic pseudomembrane |
Pseudomembrane only microscopic |
| Necrotic crypt epithelium erupts into lumen to form pseudomembrane |
Entire upper mucosal layer may slough into lumen to form pseudomembrane |
| Hemorrhage is not prominent |
Prominent hemorrhage and capillary thrombosis |
| C difficile titers elevated |
E coli O157:H7 identified by culture |
| Associated with antibiotic therapy |
Not associated with antibiotic therapy |
| Pseudomembranous Colitis |
Ischemic Colitis |
| Diffuse |
Localized, may form a mass |
| No hyanization of lamina propria |
Hyalinized lamina propria |
| Occasional atrophic crypts |
Atrophic microcrypts common |
| Usually only superficial necrosis |
Necrosis frequently transmural |
| C difficile titer elevated |
C difficile titer negative |
| Associated with antibiotic therapy |
Not associated with antibiotic therapy |
