Allergy & Immunology > Allergy
Patients Who Say They're Allergic to Penicillin Are Usually Wrong
— All "allergic" patients should be evaluated, review concludes
by Salynn Boyles, Contributing Writer January 16, 2019
Taking a careful history of past reactions to penicillin that led to allergic designations is key to distinguishing between truly allergic patients and those who can still be treated with the antibiotic, according to a new review.
Studies suggest that around 95% of the more than 32 million people in the U.S. who have reported penicillin allergies can safely be treated with the drug or another β-lactam antibiotic, reported Erica Shenoy, MD, PhD, of Massachusetts General Hospital in Boston, and colleagues in JAMA.
The researchers presented strategies for identifying and managing penicillin allergic patients and reducing reliance on broad-spectrum antibiotics, which are leading contributors to antimicrobial resistance and resistant pathogens such as Clostridium difficile (C. difficile).
The newly published recommendations were produced by a writing committee jointly appointed by the American Academy of Allergy, Asthma and Immunology (AAAAI), the Infectious Diseases Society of America, and the Society for Healthcare Epidemiology of America.
"More than 1 in 10 people who seek medical care self-report a history of penicillin allergy," David Lang, MD, president elect of AAAAI, said in a statement. "Recent evidence has confirmed most patients with unverified penicillin allergy are needlessly avoiding penicillins."
The goal of the recommendations was to provide clinicians with tools to guide them in identifying patients who can safely be treated with penicillin based on the severity of previously reported reactions.
Shenoy and co-author Kimberly Blumenthal, MD, also of Massachusetts General Hospital in Boston, told MedPage Today that all patients with documented penicillin allergies should be asked about their reaction history in all clinical settings, from routine outpatient care to hospitalization during preparation for surgery.
If the reaction was non-allergic -- such as gastrointestinal distress, headache, nausea, or diarrhea -- or the sole risk was having a family history of penicillin allergy or a history of itching related to penicillin without rash, patients are considered to have a low penicillin allergy risk.
The writing committee concluded that drug challenge without referral to an allergist is warranted in these patients.
Moderate-risk patients include those with urticaria or other pruritic rashes and those with features of immunoglobulin E (IgE)-mediated reactions.
High-risk patients include those with a penicillin history that includes anaphylaxis, positive penicillin skin testing, recurrent penicillin reactions, or hypersensitivities to multiple β-lactam antibiotics.
"Even patients with anaphylaxis histories can be evaluated for penicillin allergies," Blumenthal said, adding that a large percentage of patients with a history of severe allergic reaction to penicillin may experience no reaction later in life.
The writing group recommended that patients with a history of high-risk reactions be evaluated by a specialist, and "if penicillin is required immediately for optimal patient care, a desensitization procedure may be pursued."
"Desensitization is reserved for scenarios in which penicillin or a penicillin-related drug is superior to alternative antibiotics," the group wrote. "Antibiotic desensitization's are frequently performed in hospitalized patients, often in the intensive care unit, because 1:1 nursing support is typically required."
Shenoy told MedPage Today that the involvement of allergists and asthma specialists, along with infectious disease specialists and healthcare epidemiologists, demonstrates the wide interest in the topic of penicillin allergy over-reporting.
"We all separately have been interested in evaluating penicillin allergy for the purposes of antibiotic stewardship and improving patient outcomes," she said.
In their latest issue, JAMA included an illustrated page that clinicians can use to help patients understand penicillin allergy. Shenoy said clinicians can also download tool kits from JAMA's website that they can modify to fit their own practices.
"We encourage them to reach out to allergy specialists in their local area to develop protocols together," she said. "We are hopeful that there will be a lot of interest in this, given the endorsement of all three societies. This manuscript is meant to be used, not just read."
Shenoy and Blumenthal reported copyright on a clinical decision support tool for penicillin allergy evaluation. One co-author reported being a partner in the Southern California Permanente Medical Group and receiving grants from ALK-Abelló to study adverse drug reactions during the conduct of this study.
Source Reference: Shenoy E, et al "Evaluation and management of penicillin allergy: A review" JAMA 2019; DOI: 10.1001/jama.2018.19283.