Introduction: Allergies to penicillin-based antibiotics are charted for up to 10% of the population, though it is estimated that up to 90% of these reported allergies may not be true allergies. The label of penicillin allergy (PCN-A) has been linked to an increased risk of MRSA and C difficile infection (CDI) in the general population in part due to alternative antibiotic selection. Patients with inflammatory bowel disease (IBD) are noted to have higher rates of CDI as well. The goal of this project was to assess infection and hospitalization risk in IBD patients with PCN-A.
Methods: The multi-institutional, health research network TriNetX (Cambridge, MA, USA) was queried using ICD10 codes to obtain clinical data on patients with a diagnosis of PCN-A and IBD between 2002 and 2022. Variables of interest were queried. Propensity matching was used to compare groups, and ulcerative colitis (UC) and Crohn’s disease (CD) were analyzed separately.
Results: 7,536 patients with UC and PCN-A were identified and matched to those without PCN-A based on age, sex, race, glucocorticoid use, and proton pump inhibitor use. Similarly, 8,699 patients with CD and PCN-A were matched with a non PCN-A cohort based on similar characteristics (Table 1). Both UC and CD patients with PCN-A had a significantly increased risk of developing CDI compared to those without PCN-A (OR=1.51, p< 0.0001; OR=1.53, p< 0.0001 respectively) as well as MRSA infection (OR=1.81, p< 0.0001; OR=1.76, p< 0.0001 respectively; Figure 1). There was no increased risk of having intestinal surgery in either UC or CD patients with PCN-A. PCN-A status did not alter risk of needing biologic therapy for UC patients (OR=1.0, p=0.87) but decreased likelihood for CD patients compared to non-PCN-A (OR=0.90, p=0.01). Both UC and CD patients with PCN-A had an increased risk of ER visits (OR=1.38, p< 0.0001; OR=1.47, p< 0.0001 respectively) and hospital admission (OR=1.40, p< 0.0001; OR=1.45, p< 0.0001 respectively).
Discussion: Patients with IBD and reported PCN-A have an increased risk for CDI and MRSA. These patients also had an increased risk of ER visits and admission; however, they were not more likely to require intestinal surgery. CD patients with PCN-A were less likely to receive biologic therapy. More studies are needed to explore the role of PCN-A label on outcomes in IBD patients. These patients should be considered for allergy testing as it may independently increase risk for infections.
