Antibiotic Stewardship: Defining a True Penicillin Allergy

From the 2018 HVPAA National Conference

Alexandra Lucas (Geisinger Commonwealth School of Medicine), John Orr (Geisinger Commonwealth School of Medicine), James Palma-D’Souza (Geisinger Commonwealth School of Medicine), Hannah Snyder (Geisinger Commonwealth School of Medicine), Amber Khan (Guthrie/Robert Packer hospital)


Patients with penicillin allergies in their chart are at higher risk of ICU admission/readmission, lengthier hospital stay, more antibiotic use, and morbidity and mortality.

Many patients designated as allergic to penicillin are not allergic. The severe consequences of this allergy serve as an incentive for practitioners to re-evaluate these patients.


Our primary aim was to determine whether patients listed as ‘allergic to penicillin’ in the Guthrie Robert Packer Hospital electronic medical record are truly allergic based on clinical history.


This prospective observational quality improvement study took place at Robert Packer Hospital (RPH), a 254 bed tertiary care teaching hospital in the Guthrie Health System in Sayre, Pennsylvania

Between November 1, 2017 and January 31, 2018, 62 patients were interviewed by members of the investigative team

  • Criteria: Patients admitted to RPH with a penicillin allergy documented in their electronic medical record

Each patient was asked a standard seven question survey (Table 1)

Answers to the survey questions were recorded and analyzed and patients were placed into one of three categories based on their responses:

  • Likely Penicillin Allergy – anaphylaxis, angioedema, Stevens-Johnson Syndrome, wheezing, urticaria, itchy rash (non-urticarial)
  • Possible Penicillin Allergy – Minor rash (non-itchy and non-urticarial), reaction listed as “likely” above with no reaction on a later exposure to same drug, unknown reaction when labeled as allergic
  • Unlikely Penicillin Allergy – Reaction is a known side effect of the medication, listed as allergic to penicillin on chart but denied a penicillin allergy when the survey was conducted
  • Results were then statistically analyzed


62 inpatient individuals with penicillin allergies on their electronic medical record at Guthrie Robert Packer Hospital responded to the survey presented in Table 1. Those 62 patients were split into three groups based on the criteria as reported in the methods:

  1. Likely Penicillin Allergy
  2. Possible Penicillin Allergy
  3. Unlikely Penicillin Allergy

Results (Figure 1):

  • 27% (n=17) of the patients fell into the first category
  • 60% (n=37) of the patients fell into the second category
  • 13% (n=8) of the patients fell into the third category

21 of the 62 patients reported having either penicillin or amoxicillin after already being diagnosed with a penicillin allergy. Of those 21 patients, 81% (n=17) reported having no reaction, 14% (n=3) reported a rash, and 5% (n=1) reported an anaphylactic reaction. (Figure 3)


13% of the patients fell into the “unlikely” category and could safely be removed from the patient charts.

60% of the patients could possibly have their allergy labels removed. These patients fall into the “possible” category and had minor reactions to penicillin such as nausea. Skin testing would clarify their allergy status. Although skin testing poses challenges due to availability and cost, employing this methodology lowers the number of people requiring skin testing by approximately 40%.

Most patients who had exposure to penicillin again after already being diagnosed as allergic, 81% did not have a reaction. This strongly supports that these specific individuals, and potentially, other patients with listed ‘penicillin allergies’, do not have true allergies.

Limitations include a small data set and limited time of being able to administer surveys to patients.

Implications for the Patient

The implications of this study for patient care include the ability to reclassify many patients in terms of their penicillin allergies. This would decrease the need for broad spectrum antibiotics. This increases patient safety and reduces cost for the patient.

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