Clostridioides difficile

Snapshot

• An 89-year-old man with a past medical history of gastritis presents to the hospital for dehydration and watery diarrhea. He started having diarrhea and some weakness about 2 days ago and had not been able to keep up with his fluid intake. He has been taking omeprazole for over 30 years and was recently treated with clindamycin for a soft tissue infection. On laboratory evaluation, he has a marked leukocytosis. He is started on oral vancomycin.  

Introduction

• Classification
  • Clostridioides difficile 
    • anaerobic, gram + rod
    • produces 2 toxins that bind to intestinal mucosal cells
    • forms heat and alcohol-resistant spores 
    • part of normal GI flora 
• Epidemiology
  • incidence
    • common
  • risk factors
    • recent antibiotics use
      • clindamycin 
      • ampicillin
      • cephalosporins
      • fluoroquinolones
    • proton-pump inhibitors
    • recent hospitalization
    • advanced age
• Pathogenesis
  • causes a pseudomembranous colitis and diarrhea  
    • characterized by yellow-white plaques in intestinal mucosa 
    • pseudomembranous plaques are made from fibrin 
  • toxin A is an enterotoxin that binds to the intestinal brush border
  • toxin B is a cytotoxin and depolymerizes actin, disrupting the cytoskeleton
• Prognosis
• relapse occurs in ~20% of patients

Presentation

• Symptoms 
  • crampy abdominal pain
  • anorexia
  • malaise
  • diarrhea
    • typically watery diarrhea
    • occasionally may be bloody but without frank blood
• Physical exam
  • fever
  • dehydration
  • abdominal tenderness to palpation
• rebound tenderness in severe cases

Imaging

• Abdominal radiography 
  • indications
    • if toxic megacolon is suspected
    • for quick diagnosis and assess for early intervention
  • findings
    • dilated colon
• Abdominal computed tomography (CT) 
  • indication
    • suspicion for pseudomembranous colitis
  • findings
    • marked thickening of the colonic wall (accordion sign)
    • irregularity of bowel wall
• pericolonic stranding

Studies

• Labs
  • ↑ white blood cells
  • ↓ hypoalbuminemia
  • ↑ lactate
  • diagnostic tests of the stool
    • polymerase chain reaction for the organism
    • detection of antigen
    • + fecal leukocytes
• Making the diagnosis
• based on clinical presentation and stool studies

Differential

• Ulcerative colitis 
  • distinguishing factors
    • typically presents with bloody diarrhea
    • can also present with dermatologic manifestations such as erythema nodosum
• Crohn disease 
  • distinguishing factors
    • can be bloody or nonbloody
    • can present with fistulas
• can also present with dermatologic manifestations such as erythema nodosum

Treatment

• Management approach
  • 10-day course of antibiotics
• Medical
  • oral vancomycin
    • indications
      • resistant to metronidazole
      • severe cases
  • fidaxomicin
    • indication
      • recurrent cases
  • oral metronidazole
    • indications 
      • used as an alternative if vancomycin or fidaxomicin are not available
      • used in addition to vancomycin if patients are refractory to monotherapy
      • contraindicated in the elderly
  • fecal microbiota transplant
    • indication
• recurrent cases

Complications

• Colonic perforation
  • occurs in small percentage of patients
• Toxic megacolon
• occurs in small percentage of patients