title: A prospective observational study of the effect of penicillin skin testing on antibiotic use in the intensive care unit.
abstract: 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.
authors.affiliation: Allergy Section, The Cleveland Clinic Foundation, Ohio 44195, USA.
authors.forename: Mercedes E
authors.initials: ME
authors.lastname: Arroliga
authors.forename: Christine
authors.initials: C
authors.lastname: Radojicic
authors.forename: Steven M
authors.initials: SM
authors.lastname: Gordon
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Popovich
authors.forename: C Allen
authors.initials: CA
authors.lastname: Bashour
authors.forename: Alton L
authors.initials: AL
authors.lastname: Melton
authors.forename: Alejandro C
authors.initials: AC
authors.lastname: Arroliga
mesh_terms: 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
chemical_list: D000900:Anti-Bacterial Agents; D007769:Lactams; D010406:Penicillins