A prospective observational study of the effect of penicillin skin testing on antibiotic use in the intensive care unit.
BACKGROUND
Patients with penicillin allergy admitted to the intensive care unit (ICU) frequently receive non-beta-lactam antimicrobials for the treatment of infection. The use of these antimicrobials, more commonly vancomycin and fluoroquinolones, is associated with the emergence of multidrug-resistant infections. The penicillin skin test (PST) can help detect patients at risk of developing an immediate allergic reaction to penicillin and those patients with a negative PST may be able to use a penicillin antibiotic safely.


METHODS
We determined the incidence of true penicillin allergy, the percentage of patients changed to a beta-lactam antimicrobial when the test was negative, the safety of the test, and the safety of administration of beta-lactam antimicrobials in patients with a negative test. Skin testing was performed using standard methodology.


RESULTS
One hundred patients admitted to 4 ICUs were prospectively studied; 58 of them were male. The mean age was 63 years. Ninety-six patients had the PST: one was positive (1.04%), 10 (10.4%) were nondiagnostic, and 85 (88.5%) were negative. Of the 38 patients who received antimicrobials for therapeutic reasons, 31(81.5%) had the antibiotic changed to a beta-lactam antimicrobial after a negative reading versus 7 patients of the 57 (12%) who had received a prophylactic antimicrobial (P < .001). No adverse effects were reported after the PST or after antimicrobial administration.


CONCLUSIONS
The PST is a safe, reliable, and effective strategy to reduce the use of non-beta-lactam antimicrobials in patients who are labeled as penicillin allergic and admitted to the ICU.
Arroliga
Mercedes E
ME
Allergy Section, The Cleveland Clinic Foundation, Ohio 44195, USA.
Radojicic
Christine
C
Gordon
Steven M
SM
Popovich
Marc J
MJ
Bashour
C Allen
CA
Melton
Alton L
AL
Arroliga
Alejandro C
AC
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D018432:Drug Resistance, Multiple; D006801:Humans; D007362:Intensive Care Units; D007769:Lactams; D009820:Ohio; D010406:Penicillins / Q000009:adverse effects*; D011446:Prospective Studies; D012882:Skin Tests
D000900:Anti-Bacterial Agents; D007769:Lactams; D010406:Penicillins