HIV diarrhea

Background

• Chronic diarrhea (over 28 days); can be presenting symptom of AIDS
• Less common after introduction of HAART
• Acute diarrhea common with normal and low CD4

Clinical Presentation

• Ascertain whether small bowel vs large bowel diarrhea
  • Small Bowel
    • Diarrhea watery and copius
    • May have weight loss
    • Bloating, gas, cramping
    • Vit B12 deficient if terminal illeum involved
  • Large Bowel
    • Frequent small volume, possibly painful stools
    • Hematochezia - Consider opportunistic pathogens, also consider classic hemorrhagic bacteria (E. coli O157, Campylobacter, Shigella, Salmonella, Yersinia)
• Weight loss is concerning for infiltrative disease, opportunistic infx
• Receptive anal sex - consider local HSV, Gonorrhea, Chamlydia, Entamoeba

Differential Diagnosis

CD4 200-500

• Consider routine pathogens causing Diarrhea
  • Viruses (Norovirus, Rotavirus, Adenoviruses, Astrovirus, etc.)
  • Bacteria (Salmonella, Campylobacter, Shigella, Enterotoxigenic E. coli, C. dif, etc.)
  • Protozoa (Cryptosporidium, Giardia, Cyclospora, Entamoeba, etc.)
• Side effect of nelfinavir and ritonavir
• Kaposi Sarcoma
• Cryptosporidium parvum (brief course of illness) - severe watery diarrhea
• C. dif if abx exposed

CD4<200

• Microsporidium
• Cryptosporidium
• Histoplasma
• Lymphoma
• Enteroaggregative Escherichia coli (EAEC) (can also affect immunocompetent children)
• HIV can directly infiltrate bowel wall leading to diarrhea

CD4 <100

• Cryptosporidium parvum (chronic course of illness)
• M. tuberculosis (disseminated disease increasingly likely <100)
• Cryptococcus
• Isospora

CD4 <50

• Mycobacterium avium complex (MAC) - infiltration of bowel assoc with malabsorption
• CMV

Diagnosis

• Many workups will be non diagnostic
• Start with stool WBCs, cultures, Ova and Parasites x3, C. Dif toxin
• Acid fast smear to assess for Cryptosporidium, Isospora, and Cyclospora
• CD4<100 - Microsporidium more likely, test with Trichrome staining
• Blood cultures with fungal/acid fast if disseminated disease a concern
• Endoscopy
  • Indicated if w/u is negative and severely immunocompromised
  • Small bowel bx to look for MAC, lymphoma, or Microsporidiosis
  • Guaic postive stools and weight loss, consider Kaposi Sarcoma of bowel, dx with colonoscopy
• Imaging
  • Generally not helpful, but could be indicated if severe tenderness, peritonitis, concern for biliary pathology, obstructing lesions.

Management

• Electrolyte and volume replacement
• Early consultation of HIV service
• Nutrition replacement in chronic small bowel disease
• HAART
• Generally, avoid starting antibiotics unless have specific target
• Antimotility agents
  • loperamide
  • crofelemer (blocks chloride secretion and approved for HIV diarrhea) 125 mg po bid

Disposition

• If near normal CD4 and symptoms consistent with small bowel disease (copious, watery), may be managed as outpatient if no other admission indication
• Severe dehydration, electrolyte abnormalities, malnutrition, fever, and hemorrhagic diarrhea all may require admission or at minimum very close HIV f/u

See Also

HIV (CD4) HIV - AIDS (Main) Diarrhea

References

UpToDate: "Evaluation of the HIV-infected patient with diarrhea" https://www.aids.gov/hiv-aids-basics/staying-healthy-with-hiv-aids/potential-related-health-problems/opportunistic-infections/