Penicillin allergies are perhaps among the most commonly self-diagnosed affliction in medicine. While 10 percent of Americans report an allergy to the antibiotic, the vast majority are likely misinformed.
A simple rash in childhood is often mistaken for a sensitivity to the antibiotic, leading many to avoid this vital medication for no reason.
The “epidemic” of false penicillin allergy claims is a very real concern for medical professionals, Dr. Nima Majlesi, director of medical toxicology at Northwell Staten Island University Hospital in New York, told The Epoch Times.
It limits treatment options and fuels antibiotic resistance. New research aims to set the record straight, ensuring this potentially lifesaving drug can be used safely by all who need it.
Incorrect Penicillin Allergy Labels Put Patients at Risk
While adverse reactions are common with medications, true allergies eliminate entire classes of drugs, which can severely impact care.
Incorrectly labeling someone as being allergic to penicillin may lead to the use of less effective antibiotics, and increase the risk of antibiotic resistance, infections, and adverse reactions like Clostridioides difficile (C. difficile) colitis, a potentially fatal infection that can cause severe dehydration and kidney failure.
Proper allergy testing is crucial yet limited. Current testing involves pricking the skin and applying penicillin to check for reactions. Patients without reactions get an oral dose to confirm. But few have access to specialist-trained allergy physicians for skin testing, according to Dr. Majlesi.
A new randomized clinical trial may help more patients remove incorrect allergy labels to access lifesaving penicillin when needed.
Oral Penicillin Shown as Effective as Skin Test for Low-Risk Patients
Called the PALACE study, the research was recently published in the Journal of the American Medical Association (JAMA). It could expand testing by showing an oral dose alone is as effective as skin testing for low-risk patients.
The 382 adults who participated were initially evaluated using the PEN-FAST risk assessment tool for low risk. They were randomly assigned to two groups. One group underwent skin testing, followed by an oral test dose of penicillin if the skin test was negative. The other group received a direct oral test dose, known as a “direct oral challenge.”
The study aimed to compare the effectiveness of the direct oral penicillin with the standard skin method.
Results showed that only one patient in each group experienced an allergic reaction to the oral penicillin, indicating it is as effective as the currently used two-step test in testing for allergy. Additionally, no significant differences in adverse reactions were observed between the two groups, and no serious adverse events occurred.
“The majority of patients labeled as penicillin allergic, more than 90 percent, have low-risk histories, meaning they did not have a history to suggest a severe or more recent reaction to a penicillin,” Dr. Elizabeth Phillips, PALACE study protocol member and principal investigator, said in a press statement. “We would expect more than 95 percent of these [low-risk, according to PEN-FAST test] patients to have negative testing and be able to take penicillin in the future.”
Gradual Exposure Allows Some Allergic Patients to Take Penicillin
For patients with confirmed penicillin allergy who need the drug to treat an infection, desensitization, consisting of gradually increased exposure to penicillin, may allow safe administration.
This process has been used to enable treatment with medications to which a patient is allergic when no alternatives exist, Dr. Majlesi said.
It involves exposing the patient to very small, nonreactive doses of the allergen. The doses are gradually increased at set intervals to build tolerance to therapeutic levels. “This leads to tolerance to the drug or substance,” Dr. Majlesi added.
However, tolerance requires adhering to the full antibiotic course as directed. Patients will likely need repeat desensitization if prescribed penicillin again in the future.
While often successful, desensitization carries risks and is not always effective.