Colon
Noninfectious colitis
Pseudomembranous colitis
Author: Hanni Gulwani, M.B.B.S.
Last author update: 1 May 2013
Last staff update: 3 May 2022
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: antibiotic associated colitis
Table of Contents
Definition / general | Clinical features | Diagnosis | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stainsCite this page: Gulwani H. Pseudomembranous colitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colonAAcolitis.html. Accessed April 1st, 2023.
Definition / general
- Also called pseudomembranous colitis
- Acute colitis with adherent inflammatory exudate (pseudomembrane) overlying sites of mucosal injury, usually after broad spectrum antibiotics (clindamycin, lincomycin, others), which favor the overgrowth of Clostridium difficile over other gut bacteria (Merck manual, eMedicine #1, #2)
- Also after surgery or chronic debilitating illness without antibiotics
- Clinical disease is due to toxins (Clin Microbiol Rev 2005;18:247, Indian J Med Res 2010;131:487)
Clinical features
- Symptoms: acute or chronic diarrhea; may cause toxic megacolon and perforation
- 25% caused by Clostridium difficile; other pathogens include Clostridium perfringens, Staphylococcus aureus, Klebsiella oxytoca, Candida and Salmonella species (Indian J Med Microbiol 2003;21:6)
- Non-infectious causes include reduced breakdown of primary bile acids, decreased metabolism of carbohydrates, allergic or toxic effects of antibiotics on intestinal mucosa and pharmacological effects on gut motility
- Increasing rates in elderly (Emerg Infect Dis 2006;12:409, Nippon Ronen Igakkai Zasshi 2002;39:271)
- Severe cases also reported in low risk populations (MMWR Morb Mortal Wkly Rep 2005;54:1201, Lancet 2005;366:1079); may be associated with fluoroquinolone use (Infect Control Hosp Epidemiol 2005;26:273)
- Clostridium difficile, a normal gut commensal, may produce toxin A, which causes intestinal secretion and acute inflammation
- Clostridium difficile toxin in stool does not correlate with presence of Clostridia and may not contribute to pathology in intestinal tissues of children (Hum Pathol 2010;41:1586)
Diagnosis
- Detect Clostridium difficile toxin (toxin A-enterotoxin or less commonly toxin B-cytotoxin) in stool (Am J Med 2006;119:356.e7, J Clin Microbiol 2006;44:1145)
- Must interpret results within context of patient history and clinical features (Am J Clin Pathol 2012;137:10)
- Suggested to accept only loose or liquid stool specimens for analysis; monitor / regulate test-ordering practices such as repeated requests after negative results, testing for cure, testing of infants and children
Case reports
- 74 year old man post-antibiotics for vascular surgery (Univ Pittsburgh Case 153)
Treatment
- Vancomycin or metronidazole; 25% may relapse; toxoid vaccine may be effective in recurrent cases (Gastroenterology 2005;128:764)
Gross description
- Yellow-white mucosal plaques or pseudomembranes; may resemble polyps or aphthoid ulcers of Crohn's disease
Gross images
Images hosted on other servers:
Hyperemic mucosa and green-yellow exudate
Pseudomembranous colitis
Microscopic (histologic) description
- Denuded epithelium
- Mucopurulent exudate erupts out of crypts to form a mushroom-like cloud with a linear configuration of karyorrhectic debris and neutrophils that adheres to surface
- Superficial crypts show patchy necrosis and dilation
- Later in disease, entire crypt becomes necrotic and disease resembles ischemic colitis
- Adjacent mucosa is normal, but may be covered by pseudomembrane
- Superficial lamina propria contains dense neutrophils and some capillary fibrin thrombi
- Rarely signet ring cell change (Am J Surg Pathol 2004;28:1111)
Microscopic (histologic) images
Images hosted on other servers:
Pseudomembrane with intact mucosa
Eruption of exudate resembling mushroom cloud
Superficial ulcer /
pseudomembrane
Various images
Pseudomembranous colitis
Pseudomembrane contains abundant neutrophils
Positive stains
- Higher rates of C difficile can be detected by GDH assay or real time PCR based testing than by EIA alone (Arch Pathol Lab Med 2012;136:527, Arch Pathol Lab Med 2012;136:20)
