HIV diarrhea
Background
- Chronic diarrhea (over 28 days), can be presenting symptom of AIDS
- Less common after introduction of HAART
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)
- Small Bowel
- Weight loss is concerning for infiltrative disease, opportunistic infx
- Receptive anal sex - consider local HSV infx, Gonorrhea, Chamlydia, Entamoeba
Differential Diagnosis
CD4>200
- Consider routine pathogens causing Diarrhea
- Viruses (norovirus, rotavirus, adenoviruses, astrovirus, etc.)
- Bacteria (salmonella, campylobacter, shigella, enterotoxigenic E. coli, C. difficile, etc.)
- Protozoa (cryptosporidium, giardia, cyclospora, entamoeba, etc.)
- Side effect of nelfinavir and ritonavir
- Kaposi
- Cryptosporidium parvum (brief course of illness) - severe watery diarrhea
- C. diff if abx exposed
CD4<200
- Microsporidium
- Cryptosporidium
- 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)
- Mycobacterium avium complex (MAC) - infiltration of bowel assoc with malabsorption
- Histoplasma
- Cryptococcus
- CMV
- Isospora
Diagnosis
- Many workups will be non diagnostic
- Start with stool WBCs, cultures, Ova and Parasites x3, C. Diff 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
Disposition
- If near normal CD4 and symptoms consistent with small bowel disease (copius, watery), may be managed as outpatient if no other admission indication
See Also
References
UpToDate: "Evaluation of the HIV-infected patient with diarrhea"