Few patients receive penicillin allergy test before hematopoietic stem cell transplant
Key takeaways:
- Researchers found a penicillin allergy label in 12% of a population of 1,359.
- Before transplant, only three patients received either a penicillin or cephalosporin allergy test.
SAN DIEGO — Before undergoing hematopoietic stem cell transplant, over 10% of patients had a penicillin allergy label but less than 1% had been tested for this allergy, according to a presentation here.
This cross-sectional study was presented at the 2025 American Academy of Allergy, Asthma and Immunology/World Allergy Organization Joint Congress.
“Because patients with stem cell transplants have very high morbidity and mortality from infections, and optimizing antibiotic selection is critical in this population, we were expecting that a good proportion of patients would have their allergy labels evaluated prior to transplant,” Ami Belmont, MD, allergy and immunology physician at Yale Medicine, told Healio. “However, we found that very few patients in our study had their antibiotic allergy labels evaluated prior to transplant.”
In this study, Belmont and colleagues analyzed 1,359 patients (median age, 60 years; 38% female; 71% white) undergoing a hematopoietic stem cell transplant (HSCT) — either autologous or allogenic — between 2013 and 2023 to determine how prevalent penicillin allergy labels and allergist testing are before the transplant.
The Yale New Haven Hospital electronic medical record and transplant registry was the source for data on these patients, according to the abstract.
Researchers found a penicillin allergy label in 12% (n =163) of the study population. Other antibiotic allergy labels observed in those undergoing HSCT included sulfonamide (6%; n = 85) and cephalosporin (2%; n = 32).
“We expected that reported antibiotic allergies that are common in the general population (eg, penicillin, cephalosporin and sulfonamide allergy labels) would also be common among patients with stem cell transplants, and they were,” Belmont told Healio. “In the general population, we know that, for instance, greater than 95% of patients who report a penicillin allergy are not allergic.”
Within the cohort of patients with a penicillin allergy label, the abstract reported significant differences in the prevalence of this label in the sex and race subgroups, with a greater prevalence in females vs. males and white vs. non-white patients.
“Female patients seem to be at particularly high risk for antibiotic allergy labels,” Belmont told Healio. “Given that the majority of patients with these antibiotic allergy labels can likely tolerate these antibiotics, there is a need to evaluate these allergy labels in more patients prior to transplant.”
The prevalence of penicillin allergy labels did not significantly differ based on age, ethnicity or primary English speakers, according to the abstract.
In terms of allergy testing before HSCT, researchers found that only three patients received either a penicillin test (n = 1; < 1%) or a cephalosporin test (n = 2; 6%).
“It will be important for future studies to address specific risks of entering a stem cell transplant with antibiotic allergy labels,” Belmont told Healio. “Patients may be at risk for similar complications to the general population, as well as transplant-specific risks.”
Reference:
- Hematopoietic stem cell transplant patients rarely tested for penicillin allergy. https://www.aaaai.org/about/news/news/2025/hematopoietic. Published Feb. 10, 2025. Accessed Feb. 10, 2025.