Immediate Hypersensitivity Reactions to Biologic Drugs in Children with Inflammatory Bowel Diseases

Introduction: The increased use of biologic drugs (BDs) may lead to an increase in immediate hypersensitivity reactions (I-HSRs) in pediatric patients with inflammatory bowel disease (IBD). Our aim was to assess I-HSRs to BDs in pediatric IBD, examining frequency, clinical features, management, and associated risk factors. Methods: All children diagnosed with IBD at our institution between January 1, 2006, and August 1, 2023, and who developed I-HSRs related to any BD were included in the study. Results: In a study of 197 pediatric IBD patients, 61 used BD. Among these, 52.4% were male, with a median diagnosis age of 145 months (13–215). Out of a total of 1,679 administrations, 6 patients developed I-HSRs (5 with infliximab, 1 with adalimumab), resulting in a frequency of 9.8% per patient and 0.36% per administration. Of these, 66.7% were cases of Type 1 HSRs (skin test positivity n = 1), while the rest were infusion-related reactions (anti-drug antibody positivity n = 4), all of which were mild to moderate in severity. In the age and gender-adjusted logistic regression model, the presence of any comorbid allergic disease was significantly associated with the occurrence of I-HSR (aOR = 8.35; 95% CI = 1.24–56.38; p = 0.029). Conclusion: The frequency of I-HSRs to BDs in children with IBD is not rare but not severe in the long term. The presence of any comorbid allergic disease is a risk factor for the development of I-HSRs to BDs.