Case summary: Thanks to Rand and Akshai for presenting a great case– an 84M with a history of gout who presented with RUE cellulitis complicated by GNR bacteremia after being bitten by his cat, Leo, who then developed olioarticular arthritis of the R DIP and PIP joints due to gout that improved on anakinra.
- In contrast to Staph bacteremia, GNR bacteremia should trigger you to think of: a shorter duration of therapy (7-14 days depending on clinical response), faster switch to oral therapy (48-72H afebrile and hemodynamically stable), and no need for surveillance blood cultures.
- Non-purulent cellulitis can take 48-72H to show clinical improvement (downtrending WBC count, afebrile, erythema/edema receding), so hold off on escalation of antibiotics!
- The pattern of joint involvement is useful in determining your pre-test probability for septic arthritis– it typically causes monoarticular or at least contiguous arthritis in larger joints, rather than the oligoarthritis in the small joints seen in this patient.
- Anakinra (an IL-1 agent) is an option for patients with gout who have contraindications to traditional therapies (e.g. steroids, NSAIDs)
Gram-negative rod bacteremia pearls c/o Andrew Kerkhoff
- Earlier in the year, Dr. Kerkhoff– ID fellow extraordinaire– gave us some fantastic pearls about GNR bacteremia during an M+M
- Community: GU>>>GI>respiratory tract
- Hospital: GU>>central lines/wound infections>GI>respiratory tract
- Risk factors:
- Immunocompromised hosts (stem cell transplant/hematologic malignancy, solid organ transplant, diabetes, HIV, steroids, elderly)
- Other organ dysfunction (ESLD, ESRD on HD, chronic pulmonary infection)
- Microbiology: Klebsiella, Pseudomonas, Enterobacteriacae, SPACE organisms
- High mortality rate (12-38%)
- Increasing drug resistance (to CTX/Zosyn)
- Duration: few RCTs and driven by site/severity of infection/response to treatment, but generally 7-14 days
- Switch to oral: within 48-72H of normothermia and normal VS
- Follow-up blood cultures: bacteremia is usually transient and clears quickly with therapy, and the value of repeat blood cultures is unclear given they are rarely positive
Cellulitis pearls c/o Jen Babik
- In general, we expand antibiotics too soon in cellulitis, as clinical response (e.g. reduction in edema/erythema, decrease in WBC count, defervesence) can take 48-72 hours.
- For patients who are not improving by 72H, in addition to “wrong bug/wrong drug” that would support switching antibiotics, also consider the following:
- lack of source control (e.g. abscess, osteomyelitis)
- vascular insufficiency (venous stasis or arterial insufficiency + inadequate elevation)
- alternative diagnosis (e.g. venous stasis, drug reaction, etc.)