A descriptive analysis of published case reports of severe allergic reactions induced by rituximab

This study aimed to characterize the clinical profile of severe allergic reactions associated with rituximab therapy. We conducted a descriptive, retrospective analysis of published case reports and case series. Relevant reports published between January 2000 and October 2025 were identified through searches of PubMed, Embase, China National Knowledge Infrastructure, Chinese Science and Technology Journal Database, and WanFang databases. Data on patient demographics, clinical presentation, management, and outcomes were extracted and analyzed descriptively. A total of 24 documented cases were included. Patients had a mean age of 46.4 years, with a range of 6 to 86 years. Females accounted for 54.2% of the cases. The most frequent underlying condition was hematological malignancy, reported in 58.3% of patients. The majority of allergic reactions occurred within 24 hours of infusion, and nearly half occurred during the initial administration. Notably, in the included cases, 75.0% of patients developed severe reactions despite the administration of standard premedication. Predominant symptoms were dyspnea (37.5%), chest tightness (29.2%), laryngeal edema (25.0%), chills (20.8%), and hypotension (16.7%). According to the World Allergy Organization criteria, 75.0% of the cases met the diagnostic criteria for anaphylaxis. Primary management strategies included discontinuation of rituximab (79.2%), corticosteroids (54.1%), epinephrine (37.5%), and antihistamines (37.5%). While most patients (83.3%) improved following intervention, 20.8% required care in an intensive care unit or emergency department. Causality assessment using the Naranjo scale rated the association as "probable" in 58.3% of cases and "certain" in 25.0%. Rituximab can induce severe and potentially life-threatening allergic reactions. These reactions may occur in patients of any age, during any treatment cycle, and even after prophylactic medication has been administered. Most reactions are acute in onset and primarily involve the respiratory and cardiovascular systems. These findings highlight the importance of close monitoring and prompt intervention during rituximab therapy. Further studies are needed to refine preventive and management strategies.