NEWS
Dr. Nina Mörsch | 07 May 2024
Penicillin allergies are less prevalent than often presumed. However, misdiagnosed allergies can prove detrimental to patients requiring antibiotic therapy and contribute to antibiotic resistance. Professor Norma Jung from the University Hospital Cologne, Germany, presented a new recommendation at the 130th Congress of the German Society for Internal Medicine, from the ‘Choosing Wisely’ initiative for assessing suspected penicillin allergies.
This article is based on the presentation titled ‘Review of a history of penicillin allergy before starting antibiotic therapy’ presented by Jung at the Congress.
Imagine a scenario: A 55-year-old patient presents to the emergency room with fever and a swollen, warm joint. Despite stable cardiopulmonary status, she recalls experiencing diarrhoea and nausea about 10 to 15 years ago after taking amoxicillin, although the symptoms resolved spontaneously.
Examinations reveal leukocytosis of 15,000/µL and significantly elevated C-reactive protein levels at 150 mg/L (normal value 5 mg/L).
Further investigations including blood cultures and joint aspiration confirm the presence of Staphylococcus aureus, susceptible to flucloxacillin, cefazolin, and vancomycin. The diagnosis is septic arthritis with S. aureus bloodstream infection.
“What would you do?” Jung asked the audience.
New ‘Choosing Wisely’ Recommendation
The majority of respondents indicate they would initially assess allergy risk based on medical history. According to Jung, this is a wise choice. Despite approximately 5%-10% of patients claiming penicillin allergy, Jung asserted this figure is much too high.
Literature indicates that only about 1% of the population actually has a ß-lactam allergy. Nonetheless, suspected penicillin allergies are often noted in patient records. Such patients frequently receive second-line antibiotics, while ß-lactams are needlessly avoided, despite their crucial role in treating bacterial infections. Thus, the new ‘Choosing Wisely’ recommendation states: “Patients with a history of penicillin allergy should undergo thorough evaluation before starting antibiotic therapy to avoid unnecessary use of second-line antibiotics.”
Misinterpretation of Side Effects as Allergy
Jung explained that symptoms following antibiotic administration, such as diarrhoea or nausea, are often misinterpreted as allergies, despite often being mere side effects of the antibiotics or signs of a viral infection with exanthema.
Jung stressed that this misinterpretation poses a significant challenge as it often leads to the use of second-line antibiotics. This not only results in increased resistance development, higher rates of side effects, and rising therapy costs but also leads to inferior treatment outcomes.
In a cohort study examining mortality 30 days after ß-lactam therapies compared with vancomycin therapies, notable findings emerged. There was a significant reduction in mortality associated with penicillin use.
“It’s important for us to recognise that withholding these more effective antibiotics could lead to poorer patient outcomes,” emphasised Jung.
In this context, Jung recalled a prior ‘Choosing Wisely’ recommendation regarding S. aureus bloodstream infection, in which the importance of consistent therapy as well as focused search and remediation was emphasised. Consistent treatment entails appropriate duration and the use of suitable medication.
PEN-FAST Score Facilitates Delabelling in Everyday Practice
Acknowledging the complexities and uncertainties inherent in everyday therapy, Jung introduced a straightforward tool, the ‘PEN-FAST score’, aimed at facilitating safe ß-lactam therapy for patients.
PEN-FAST SCORE
F – Five or fewer years since response (2 points)
A – Anaphylaxis or angiooedema
S – OR severe reaction to the antibiotic (2 points)
T – The reaction is treated (unknown; 1 point)
Table: A score of <3 indicates a low risk for penicillin allergy
A maximum of five points can be achieved with the PEN-FAST score. If the score remains below three, a penicillin allergy is unlikely. Jung elaborated that a point is also assigned if patients are unsure about their penicillin allergy status.
This scoring system facilitates a quick assessment, particularly regarding severe reactions such as anaphylaxis or angiooedema within the last 5 years, aiding in therapy decision-making. An online calculator can be assessed here.
This story was translated from Coliquio using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
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