Chapter 34, Ep 3 of 4: HIV GI Disease and Typhlitis

Episode three covers the non-transplant immunocompromised GI host, where two settings that look unrelated share one logic: identify the host state, and the host state opens a tiered differential. In HIV that state is the CD4 count, which converts a long pathogen list into strata that drive workup and surfaces the pre-antiretroviral-era entities still seen in late presenters, AIDS cholangiopathy, gut Kaposi sarcoma, and post-treatment IRIS. In chemotherapy-related neutropenia that state is the absolute neutrophil count, which defines typhlitis as a cecum-predominant enterocolitis managed conservatively with bowel rest and broad-spectrum antibiotics. The recurring move is that the number tells you what to look for and the entity tells you what to do, from antiretroviral therapy as the dominant intervention to the narrow list of surgical indications.   Topics covered CD4 count as the HIV recognition anchor CD4-stratified opportunistic infection tiers AIDS cholangiopathy and papillary stenosis GI Kaposi sarcoma and HHV-8 Immune reconstitution inflammatory syndrome Antiretroviral timing and the cryptococcal exception Typhlitis pathogenesis and the recognition triad Conservative management and surgical indications   Key decisions Let the CD4 stratum set pretest probability: below one hundred directs stool studies for Cryptosporidium and microsporidia plus blood cultures for Mycobacterium avium complex. Add ERCP sphincterotomy for the papillary stenosis pattern of AIDS cholangiopathy, because fixed scar does not reverse with antiretroviral therapy alone. Diagnose GI Kaposi sarcoma by clinical appearance at endoscopy rather than pinch biopsy, confirming with LANA-1 immunohistochemistry and treating primarily with antiretroviral therapy. At IRIS, continue antiretroviral therapy without interruption and treat the underlying infection, delaying initiation four to six weeks only for cryptococcal meningitis. Diagnose typhlitis on CT showing cecal wall thickening greater than four millimeters and avoid colonoscopy, which risks perforation in a friable neutropenic bowel. Manage typhlitis conservatively with bowel rest and antibiotics covering gram-negatives, anaerobes, and Pseudomonas, adding empiric antifungals after seventy-two hours of persistent fever. Reserve surgery for perforation, refractory hemorrhage, full-thickness necrosis, persistent sepsis, or abscess failing drainage, accepting operative risk when the alternative is death.   For the full chapter with MCQs, tables, and primary-guideline references, visit www.boardpearls.com. Questions or feedback: [email protected]. (00:00) - Two host states, one recognition logic (01:27) - The CD4 count as the HIV anchor (03:06) - AIDS cholangiopathy and papillary stenosis (04:38) - Gut Kaposi sarcoma and immune reconstitution (06:17) - IRIS and antiretroviral timing (09:12) - Typhlitis: recognizing neutropenic enterocolitis (12:06) - Conservative management of typhlitis (14:59) - When conservative management ends and surgery begins