Strategies to identify and prevent penicillin allergy mislabeling and appropriately de-label patients

Considerations in special populations. Evaluating penicillin allergy during routine care is key to decreasing the necessity for urgent penicillin evaluation and possible desensitization at the time of serious infection. Certain patient populations pose specific challenges:

• Pregnant patients. Unverified penicillin allergy during pregnancy is associated with an increased rate of cesarean section and longer postpartum hospitalization.²⁵ Additionally, group B streptococcus-positive women have increased exposure to alternative antibiotics and an increased incidence of adverse drug reactions.²⁵
• Elderly patients. Drug allergy increases with aging.¹ Elderly patients in a long-term care facility are more likely to experience adverse drug effects or drug–drug interactions from the use of penicillin alternatives, such as clindamycin, vancomycin, and fluoroquinolones.²
• Oncology patients often require antibiotic prophylaxis as well as treatment for illnesses, such as neutropenic fever, for which beta-lactam antibiotics are often used as initial treatment.^2,26
• Other important populations that present specific challenges include hospitalized patients, pediatric patients, and patients with a sexually transmitted infection.²

Active management of a penicillin-allergy label

Greater recognition of the consequences of penicillin allergy in recent years has led to efforts by hospitals and other health care organizations to develop processes by which patients can be successfully de-labeled as part of antibiotic stewardship programs⁹ and other initiatives. Ideally, every patient who has a “penicillin allergy” label would be referred to an allergist for evaluation; however, the number of allergy specialists is limited, and access to such specialists might be restricted in some areas, making this approach impracticable. Active management of penicillin allergy requires strategies to both test and de-label patients, as well as proactive approaches to prevent incorrect labeling. These proactive approaches require involvement of all members of the health care team—especially PCPs.

Preventing incorrect labeling. PCPs are the most likely to initially label a patient as allergic to penicillin.²⁷ Most physicians rely on a reported history of allergy alone when selecting medication¹²; once a patient has been labeled “penicillin allergic,” they often retain that mislabel through adulthood.^27,28 A qualitative study of PCPs’ views on prescribing penicillin found that many were aware that documented allergies were incorrect but were uncomfortable using their clinical judgment to prescribe a penicillin or change the record, for fear of a future anaphylactic reaction.²⁹ The first step in the case of any reported reaction should be for you to elicit an accurate drug allergy history (TABLE 1).

As with other drug reactions, you should consider the context surrounding the reaction to a penicillin. Take care to review signs and symptoms of the reaction to look for clues that make a true allergic reaction more, or less, likely.

Symptoms can generally be divided into low-risk and high-risk categories²⁷ (TABLE 2). An example of a commonly reported low-risk symptom is diarrhea that develops after several doses of a penicillin. In the absence of other symptoms, this finding is most likely due to elimination of normal gut flora,³⁰ not to an allergic reaction to the medication. Symptoms of intolerance to the medication, such as headache and nausea, are also low risk.^27,31 In contrast, immediate onset of abdominal pain after a dose of penicillin and lip or throat swelling are considered high risk.

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