Recommendations from a Duke specialist regarding allergy assessment—specifically, the need to question and correct penicillin (PCN) histories—are the subject of a popular advisory column published by the Society of Hospital Medicine. Patricia L. Lugar, MD, an allergy physician and specialist in primary immune deficiency, developed the recommendations based on her work in Duke’s Asthma, Allergy and Airway Center.
“Reported PCN allergies continue to be the main reason we prescribe so many broad-spectrum antibiotics,” Lugar says. “In many cases, these allergies simply do not exist in patients who believe they have them."
Obtain a thorough drug allergy history. Ancillary staff records medical histories and medication allergies in most clinics. Lugar says physicians should review medical allergies with patients, particularly those who may require antibiotics. “It’s not uncommon to find that symptoms patients attribute to medication allergies—gastrointestinal distress or hot sensations, for example—may in fact be related to another condition such as a recent episode of mononucleosis,” Lugar says.
Perform a PCN skin test (PST). Lugar recommends that an allergist conduct the test and interpret the results. Generally, a negative skin test is a positive indication that the patient will not react to penicillin. Lugar urges additional steps when a patient reports a PCN allergy. “Have the patient ingest amoxicillin and then watch them for an hour or two,” she says. “If the amoxicillin is well tolerated, the PCN allergy should be removed from the patient’s chart.”
Preemptively test PCN-allergic patients who are at high risk of requiring PCN/PCN derivative antibiotics. Perform the assessment as early as possible during a medical encounter. Patients who are immunosuppressed and those being assessed for hematologic or oncologic procedures are considered high risk. Patients scheduled for surgical or transplantation procedures are also considered at high risk. Test early, she says, to identify and prescribe targeted antibiotics that may preempt an admission. Failing to test these patients early and aggressively can contribute to a patient’s decline in a hospital setting, she says.
Create and publish protocols developed by allergists for use in outpatient settings without access to allergy specialists. “Very few hospitals have developed and published a formal allergy protocol program,” Lugar says. Duke Health is one of the only systems in North Carolina offering an allergy protocol, she adds.
Do not perform PST on patients with a history of immunologic reactions. Physicians should be alert to such conditions as Stevens-Johnson syndrome, reaction with eosinophilia and system symptoms, non-IgE-mediated allergic reactions and other subcutaneous risks. “Testing will not predict many of these reactions and they could be life threatening,” Lugar cautions. Each patient should be assessed individually. Supervised and graded challenges with oral medication may be effective.