Virginia Anesthesia Services LLC Overestimation of Penicillin Allergy  - Virginia Anesthesia Services LLC

Overestimation of Penicillin Allergy 

Beta-lactams encompass a category of potent antibiotics comprising penicillins, cephalosporins, carbapenems, and monobactams [5]. These antibiotics, known for their exceptional efficacy, safety, and affordability, are among the most prescribed worldwide and are also associated with the highest frequency of reported hypersensitivity reactions [5]. A pressing concern in healthcare is the overestimation of penicillin allergies, with growing debate on their actual prevalence and validity [1,2]. This debate carries significant implications for patient care, healthcare costs, and the emergence of antibiotic resistance [1,2]. 

Despite penicillin allergies being reported by 8–15% of the United States population, up to 95% of these reported allergies do not correspond with true allergic reactions upon testing, according to a study on whether overestimation of this allergy occurs [2]. Genuine allergic reactions involve symptoms such as nausea, vomiting, severe itching, wheezing, throat swelling, and potentially cardiovascular collapse [1]. Since most patients do not exhibit these symptoms, administering a penicillin antibiotic is generally considered safe when indicated [1]. 

Penicillin allergies can take two forms: acute (IgE-mediated) and sub-acute (IgG-mediated) reactions [3]. Acute reactions occur rapidly, leading to anaphylaxis with severe symptoms like hypotension and bronchospasm due to preformed IgE antibodies [3]. Sub-acute reactions, appearing days after treatment, include symptoms like itching and fever due to preformed IgG antibodies activating complement reactions [3]. Confirming IgE mediation is crucial to be able to safely administer penicillin or related antibiotics, a process often requiring specialized testing that underscores the complexities of penicillin allergies [3]. 

Individuals reporting a penicillin allergy should undergo comprehensive diagnostic confirmation [3,5]. The International Consensus on Drug Allergy recommends an investigative approach involving skin tests, followed by a confirmatory Drug Provocation Test (DPT) if initial results are negative [5]. Initial diagnostic steps include skin prick tests, where the skin is punctured with minute amounts of penicillin reagents, and if negative, intradermal tests are conducted by placing penicillin reagents just beneath the skin surface [5]. In cases of immediate reactions, European guidelines suggest a blood test for quantifying penicillin specific IgE, and if negative, a DPT with penicillin under close clinical observation [5]. 

To avoid potential allergic reactions, healthcare providers often choose alternative antibiotics like broad-spectrum or more potent options. However, potential overestimation of penicillin allergy could be contributing to antibiotic resistance [2,5]. Patients labeled as penicillin-allergic might experience prolonged hospital stays and increased healthcare costs due to the necessity of less effective or more expensive antibiotics [2,5]. A 2018 study examining 8,000 patients with a documented penicillin allergy revealed a 50% increased odds of surgical site infection among penicillin-allergic patients, attributed to the use of alternative antibiotics, primarily clindamycin and vancomycin [4]. The use of second-line antibiotics also resulted in elevated healthcare-related infections, including 23% increased odds of Clostridium difficile, 14% increased odds of methicillin-resistant Staphylococcus aureus (MRSA), and 30% increased odds of vancomycin-resistant Enterococcus (VRE) [4]. 

In conclusion, clinicians are challenged with distinguishing true penicillin allergies given that allergy overestimation does occur [1]. Most reported cases may not be genuine allergies, allowing safe use of ß-lactam antibiotics in more situations than currently believed [1]. Overuse of the term “allergy” prompts unnecessary broad-spectrum antibiotic treatments, increasing costs and drug-resistant bacteria emergence [1]. 

References 

  1. Bhattacharya, S. (2010). The facts about penicillin allergy: a review. Journal of advanced pharmaceutical technology & research, 1(1), 11. 
  1. Sarfani, S., Stone Jr, C., Murphy, G., & Richardson, D. (2022). Understanding penicillin allergy, cross-reactivity, and antibiotic selection in the preoperative setting. JAAOS-Journal of the American Academy of Orthopaedic Surgeons, 30(1), e1-e5. 
  1. Faitelson, Y. (2022). Current Knowledge and Management of Penicillin Allergy by Primary Care Physicians and Points for Improvement. Journal of Allergy and Clinical Immunology, 149(2), AB78. 
  1. Blumenthal, K., Ryan, E., Li, Y., Lee, H., Kuhlen, J., & Shenoy, E. (2018). The impact of a reported penicillin allergy on surgical site infection risk. Clinical Infectious Diseases, 66(3), 329-336. 
  1. Sousa-Pinto, B., Tarrio, I., Blumenthal, K., Araújo, L., Azevedo, L., Delgado, L., & Fonseca, J. (2021). Accuracy of penicillin allergy diagnostic tests: A systematic review and meta-analysis. Journal of Allergy and Clinical Immunology, 147(1), 296-308.