Would you consider levofloxacin graded challenge, extended IV aztreonam, or an alternative treatment in a patient with reported anaphylaxis to penicillin, fluoroquinolones, and cefuroxime with cavitary pneumonia secondary to Klebsiella and Pseudomonas?

The first and most important thing would be to establish whether the patient had a true penicillin (as well as other antibiotic) allergy since >90% of patients who think they are sensitive to PNC really are not. If it is established that the patient does have a PCN allergy, consultation with ID is appropriate to select which antibiotic is most likely to provide optimal clinical response. If the allergy history is suspect, a graded challenge (3-5 step depending upon physical status of the patient...

I agree. The vast majority of patients labeled “penicillin-allergic” aren’t truly allergic.

I’m not entirely sure what a levofloxacin graded challenge entails, but I assume it’s analogous to an oral desensitization or test-dose protocol similar to what we use for penicillin.

By the way, why are we treating levofloxacin as an anti-pseudomonal fluoroquinolone? Ciprofloxacin and delafloxacin have far better activity against Pseudomonas aeruginosa. When levofloxacin was introduced, it was not consid...