Antibiotic allergy in children: Can the severity and characteristics of the index reaction predict drug provocation test results?

Background: Antibiotic allergy in children is often misdiagnosed. The criterion standard for confirming drug allergy is the drug provocation test (DPT) based on the patient's history and clinical findings. Objective: This study aimed to assess whether the characteristics and the severity grades of the index reaction can accurately predict DPT outcomes in children with suspected antibiotic allergy. Methods: A retrospective study was conducted from 2014 to 2024, which included children with immediate-type index and provocation reactions. Data included age, type, duration, severity grades of reactions, and suspected antibiotic. Reactions were graded by using the Brown scoring system. Statistical analyses included the Spearman correlation and kappa coefficient. Results: Seventy-three children with negative skin test results underwent DPT in this study. Urticaria was the most common reaction, which occurred in 46.6% of index and 57.5% of provocation reactions. Brown's grading showed 64 grade 1, 5 grade 2, 3 grade 3, and 1 ungraded index reactions. The Brown grading showed 64 grade 1, 5 grade 2, and 3 grade 3 reactions, and 1 ungraded index reaction. For provocation, 64 grade 1, 6 grade 2, 1 grade 3, and 2 were ungraded. There was moderate agreement between the index and provocation reaction types (kappa = 0.348; p < 0.001). A significant agreement was found between urticaria in the index reaction and anaphylaxis during the DPT (kappa = 0.173; p = 0.009). Moderate agreement was also observed for index and provocation anaphylaxis (kappa = 0.480; p < 0.001). In addition, a positive correlation was noted between the severity of the index and provocation reactions (Spearman = 0.460; p < 0.001). Conclusion: The severity and characteristics of index reactions provide valuable insight into the outcome of DPT. The Brown grading system is a valuable tool for predicting DPT outcomes, including severe reactions. Urticaria and anaphylaxis during the index reaction may be predictors of severe outcomes in DPT and should be closely monitored. Understanding the characteristics and severity of the index reaction and incorporating them into clinical practice may facilitate the prediction of DPT outcomes, guide clinical decision-making, improve diagnostic accuracy, and enhance patient safety.