Thanks to Hala for presenting the case of a middle-aged man with HIV on newly started HAART who presented with acute diffuse skin lesions concerning for infection, IRIS, or other! Great discussion about a relatively undifferentiated case!
- Necrotizing soft tissue infection of the perineum (consider as necrotizing fasciitis!)
- Can occur in women (labial/perineal involvement) but “Fournier” is technically dx in men
- All age groups but usually older men
- Breach in integrity of GI or GU mucosa
- Presentation is severe pain, can spread rapidly to abdominal wall, gluteals, scrotum/penis
- A type I necrotizing soft tissue infection (type 1 = polymicrobial, type II = group A strep)
- Caused by facultative organisms (E. coli, Klebsiella, Enterococcus) + anaerobes (Bacterioides, Fusobacterium, Clostridium, anaerobic strep)
- Tx: Early aggressive drainage/debridement (call urology stat!)
- Abx: Vancomycin + carbapenem + clindamycin (antitoxin effect vs staph/strep)
- Mortality 22-40%!
IRIS: Generally diagnosis of exclusion!
No specific diagnostic criteria, but the following should be present:
- AIDS with low pretreatment CD4 count (<100), except TB IRIS which can occur at any CD4 count!
- Virologic and immunologic response to ART
- Rule out drug resistant infection, bacterial superinfection, drug reactions, noncompliance
- Clinical manifestations of inflammation
- Temporal association between HAART initiation and onset of illness features- One week to a few months (median 48 days)
Ddx: Progression of OI, new OI, drug reaction.
Most common pathogens associated with IRIS:
- Continue ARVs in most cases unless life threatening IRIS or concern for permanent sequelae
- Steroids and NSAIDs have case report evidence to support use
- Prevention: Certain OIs should be treated for approx. 2 weeks before ARVs initiated if possible (Cryptococcus, CMV retinitis) to prevent IRIS
ARV skin reactions:
Most common are morbilliform rash sparing the face and urticaria
- Atazanavir causes benign jaundice (not an indication to stop drug)
- NNRTIs (nevirapine, efavirenz) and PIs (amprenavir, darunavir, indinavir)
- Abacavir (contraindicated if HLA-B*5701 allele), nevirapine, enfuvirtide