Discussion

PALs are widely reported but frequently inaccurate and are associated with worse health outcomes. While de-labeling inaccurate PALs represents an important opportunity to improve health outcomes on both an individual and a population level, the work required to address the sheer volume of PALs, which are reported in ∼10% of Americans, is immense. ¹ Our cohort of empaneled primary care patients revealed an even higher rate of PALs at ∼20%. Confounding this issue further, especially in the United States, is limited access to specialist and even primary care, particularly in rural communities. ⁵ Thus, creative approaches to optimally and safely reduce PALs that utilize existing resources and workflows while limiting strain on primary care are desperately needed.

One such approach that we’ve described herein is nurse-driven direct-to-patient messaging with education and optional allergy referral. We found this approach to be an effective method of reducing inaccurate PALs in the outpatient setting. Our intervention was most clinically significant for our patients with PALs that were unknown, followed by patients with PALs listed as rash, then hives, and itching. Of the patients who completed allergy testing in our cohort, 96.6% (84/87) were negative. This is in-line with other de-labeling projects conducted in the obstetric, surgical, oncology, pediatric, military, and inpatient settings, which achieved 86%–99% reduction in PALs. ^{Reference Samarakoon, Accarino and Wurcel6} Moving forward, we will focus our finite resources on the top two PALs that demonstrated the highest yield PAL reduction, which were unknown and rash, at our institution’s other primary care sites.

Regarding specific allergy types, “unknown” reactions most likely occurred in childhood or remote past, if at all. Reactions that occurred greater than 5 years ago without memorable reaction or treatment are considered low risk for true allergy. ^{Reference Trubiano, Vogrin and Chua7} The majority of rashes are more likely due to infection-related exanthem than a true allergy. ^{Reference Caubet, Kaiser and Lemaitre8} In our cohort, hives and itching had the lowest response rates and thus the lowest rates of de-labeling. We hypothesize that the perceived severity (eg hives) and the association with a specific negative symptom (eg itching) may have contributed to the lower response rates in these populations; however, additional studies on patient perceptions of allergies are needed.

This study has several limitations that may limit generalizability to other institutions or practices, including access to in-network allergy referral and a patient population with high utilization of out online patient messaging platform, which may have influenced our response and referral acceptance rates, respectively.

In conclusion, our nurse-driven protocol helped to specify and reduce PALs in the outpatient setting prior to acute illness, facilitating increased antibiotic options for when patients require emergency or inpatient care. Future directions include exploring the utility of using this protocol to address other PALs that may represent adverse effects rather than true allergies (eg diarrhea or vomiting) to facilitate direct de-labeling. This protocol might also be adapted and applied in other health care systems with direct patient messaging platforms.