title: Penicillin skin testing in hospitalized patients with β-lactam allergies: Effect on antibiotic selection and cost.
abstract: A history of a penicillin allergy generally leads to the use of broad-spectrum antibiotics that may increase complications and cost.
  
  
  
  To determine the cost-effectiveness of performing penicillin skin testing (PST).
  
  
  
  A retrospective analysis was conducted on adult inpatients with a β-lactam allergy who underwent PST and oral challenge performed by an allergist. The primary outcome was overall antibiotic cost savings for patients switched to a β-lactam antibiotic (BLA). Secondary outcomes included subsequent admissions that required antibiotics and total number of days a BLA was prescribed.
  
  
  
  Fifty patients had PST performed (mean age, 62 years). The most common β-lactam allergy reported was penicillin (92%). Cutaneous reactions were reported in 54% of patients, and 56% had a reaction more than 20 years ago. Fifty percent of patients had aztreonam prescribed before PST. The results of PST were negative in all patients, and 1 patient had anaphylactic symptoms during the oral amoxicillin challenge (98% skin test or oral challenge negative). Thirty-seven patients (75.5%) were changed to a BLA. Overall cost savings were $11,005 ($297 per patient switched to a BLA). There were 31 subsequent admissions that required antibiotics for patients who tested negative on skin test and oral challenge. A BLA was prescribed in 22 of 31 readmissions, totaling 147 days of BLA therapy.
  
  
  
  After the implementation of a PST protocol, we observed a decrease in non-BLA use in patients with previously documented β-lactam allergy. PST is a safe and cost-effective procedure to serve as a negative predictor test for penicillin hypersensitivity mediated by IgE.
authors.affiliation: Department of Pharmacy, Atlantic Health System, Overlook Medical Center, Summit, New Jersey. Electronic address: esther.king@atlantichealth.org.
authors.forename: Esther A
authors.initials: EA
authors.lastname: King
authors.affiliation: Department of Medicine, Banner Baywood Medical Center, Mesa, Arizona.
authors.forename: Sridevi
authors.initials: S
authors.lastname: Challa
authors.affiliation: Department of Pharmacy, Atlantic Health System, Overlook Medical Center, Summit, New Jersey.
authors.forename: Patrick
authors.initials: P
authors.lastname: Curtin
authors.affiliation: Department of Medicine, Atlantic Health System, Overlook Medical Center, Summit, New Jersey; Division of Allergy and Immunology, Rutgers University Robert Wood Johnson University Hospital, New Brunswick, New Jersey; School of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Leonard
authors.initials: L
authors.lastname: Bielory
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000191:economics; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D004342:Drug Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D010406:Penicillins / Q000009:adverse effects*; D010641:Phenotype; D012189:Retrospective Studies; D012882:Skin Tests / Q000379:methods; D057188:Workflow; D047090:beta-Lactams / Q000009:adverse effects*
chemical_list: D000900:Anti-Bacterial Agents; D010406:Penicillins; D047090:beta-Lactams