Retrospective study of 433 patients with Gram negative bacterial sepsis and history of beta-lactam allergy who received beta-lactam abx, compared with 119 similar pts who got some other abxs.
At 72-96 hours, those who got non-beta-lactams were more likely to have clinical failure (38% vs 27%, mostly continued fever).
Also less likely to get appropriate therapy based on culture results.
About 3% of patients in both groups had hypersensitivity reactions. Two pts with hx of PCN allergy (rxn unknown) had anaphylaxis, 1 got piperacillin, one cefipime.
Conclusions: In patients with severe infections, giving appropriate beta-lactam empirical therapy probably outweighed risks for hypersensitivity reaction.
Patients with a hx of allergy to one beta-lactam class (penicillin, cephalosporin or carbapenem) should receive another class.
Pts with hx of anaphylaxis should be monitored closely.
J Allergy Clin Immunol 2016 Apr; 137:1148