Abstract
Introduction
Penicillin (PCN) is one of the most common drug allergies reported in the U.S., though evidence suggests that most documented cases are not true IgE-mediated hypersensitivity reactions. Mislabeled allergies can stem from misattribution of infection symptoms and over-reliance on family history, and are associated with poor antibiotic stewardship and worsened health outcomes for patients. Although validated allergy de-labeling protocols exist, they remain underutilized in primary care settings. This student-led study evaluated the implementation of a primary care-based PCN de-labeling protocol, including patient eligibility, acceptance of testing, and the role of medical students in coordinating these efforts.
Methods
Interviewer-administered questionnaires were used to obtain allergy histories from patients with documented PCN allergies in a primary care clinic. The questionnaires included the PEN-FAST clinical decision rule (score range 0–5), which estimates the likelihood of a positive direct oral challenge (DOC). Patients scored a 0 (1% risk) if their allergy occurred more than five years ago, their history did not include symptoms of anaphylaxis or severe cutaneous adverse reactions, and they did not require treatment. These individuals qualified for allergy de-labeling without challenge, though optional testing was offered. Patients who scored 1–2 (5% risk) were eligible for a DOC with oral amoxicillin. To assess patient acceptance of de-labeling and identify potential barriers to implementation, participants were asked about their willingness to undergo DOC and, when testing was declined, their reasons for hesitancy. The timing of allergy-related discussion relative to study consent was also recorded to evaluate whether prior discussion influenced participation.
Results
139 of 157 (89.5%) patients consented to participate in the study. Patients who discussed their allergy before consenting were significantly less likely to enroll than those who did not (77.1% vs. 92.2%, p = 0.018). Among participants who did consent, 44 scored 0, and 43 scored 1-2. Grouped analysis (0, 1-2, 3-5) demonstrated no significant association between PEN-FAST score and willingness to undergo a DOC (p = 0.26). Among patients who declined testing, the most commonly cited reason was concern about another allergic reaction (n = 11).
Conclusion
Primary care-based PCN allergy screening identified 32.1% of participating patients as eligible for DOC. Although PEN-FAST score was not significantly associated with willingness to undergo DOC, concerns about experiencing another allergic reaction were the most commonly reported barrier to testing. These findings highlight both the potential for structured PCN allergy screening to expand access to de-labeling and the importance of addressing patient concerns during the process. The successful coordination of screening by medical students, initiation of DOCs at the original clinic, and expansion of recruitment to a second facility further demonstrate the feasibility of integrating a student-led de-labeling approach into primary care.