Penicillin Allergies Among Patients Undergoing Hematopoietic Stem Cell Transplants

Ami Belmont, MD

Credit: Yale School of Medicine

Approximately 90,000 people receive hematopoietic stem cell transplants worldwide annually. These patients are immunocompromised and highly vulnerable to infections, including with multi drug-resistant organisms. Because penicillin and related beta-lactam antibiotics are used as preferred therapy for many infections, patients who are labeled as having a penicillin allergy are at risk for inferior treatment and related clinical consequences.

The majority of patients who report penicillin allergy can actually tolerate penicillin, though the labeling of “penicillin allergy” leads to the use of alternative antibiotics, which are often more broad spectrum, less effective, and more toxic. In turn, penicillin allergy labels are associated with more severe infections, multi drug-resistant infections, and increased mortality.

Belmont et al. authored a comprehensive review, advocating for a multidisciplinary approach to evaluating penicillin allergy labels and providing evidence-based guidance on how to evaluate them safely.

Clinical decision tools exist to aid the clinician in assessing a penicillin allergy and can be used to risk stratify patients in order to determine a testing strategy. Patients with low-risk histories can safely undergo direct oral challenges while patients with high-risk reaction histories should undergo skin testing and oral challenge.

“Most patients who report a penicillin allergy can actually tolerate penicillins and other beta-lactam antibiotics. Although penicillin allergy labels are largely erroneous, patients with penicillin allergy labels are more likely to receive alternative antibiotics, suffer from more severe and multi-drug-resistant infections, and have increased healthcare utilization and cost. There is an urgent need to design interventions to expand access to evaluation, which can immediately restore access to preferred narrow spectrum antibiotics and improve outcomes,” said Belmont.

To learn more, read the article, “A call to address penicillin allergy labels in patients with hematopoietic stem cell transplants: How to avoid rash decisions.”

Belmont AP, Stone CA Jr, Guyer AC, Edelman EJ, Trubiano JA. A call to address penicillin allergy labels in patients with hematopoietic stem cell transplants: How to avoid rash decisions. Transpl Infect Dis. 2024 Aug 5:e14350. doi: 10.1111/tid.14350. Epub ahead of print. PMID: 39101669.