Tuesday, May 21, 2019

Beta-lactam allergies

PulmCrit (EMCrit)
PulmCrit - May 20, 2019 - By Josh Farkas
Kimberly Blumenthal and colleagues at the Massachusetts General Hospital have been performing groundbreaking work on beta-lactam allergies. Their work forms the foundation for much of the IBCC chapter on beta-lactam allergies (you might want to read it before this post, but if you don't have time, a one-minute synopsis is below).
One fundamental technique when approaching patients with possible beta-lactam allergy is a “graded challenge” or “test dose.” This may be used when there is some suspicion of a potential allergy. A small dose is provided initially with close supervision, to determine if the patient will react. If this is tolerated, larger doses are subsequently given. 
Historically, there has been little evidence to guide the safety and performance of this strategy. A new publication by the Blumenthal group describes their experience with this...
Summary: The Bullet
  • A test-dose strategy can be used in situations where an allergy is unlikely (yet possible), to help determine the safety of providing a full dose of antibiotic.
  • This is the largest study to validate any specific protocol for challenging patients with possible antibiotic allergy.
  • Within the context of a structured protocol, the test-dose strategy was safe and effective (even without the assistance of an allergist and outside of an ICU).
  • Administration of an advanced-generation cephalosporin using a test dose seems to be safe, even in patients with anaphylaxis to a penicillin."