Delayed hypersensitivity reactions to taxanes: Clinical presentation and outcomes of post-medication and rapid drug desensitization

Background: Taxanes are widely used in solid tumors but may induce delayed hypersensitivity reactions (DHRs), potentially compromising treatment. The aim was to characterize taxane-related DHRs and evaluate the role of post-medication and rapid drug desensitization (RDD) in treatment continuation. Methods: A retrospective, observational study at University Hospital Dr. José Eleuterio González, in Monterrey, Mexico, from January 2020 to May 2025. Patients who developed delayed HSRs following taxane administration were included. After an intravenous challenge test, a post-medication and/or a 3-bag, 12-step rapid drug desensitization (RDD) protocol was applied, adjusted per patient tolerance. Results: Among 4217 patients, 325 (7.7%) developed HSRs; 28 (8.8%) were delayed. Nine cases (32.1%) were attributed to taxanes: 66.6% paclitaxel and 33.4% docetaxel. Most patients were female (88.9%), with a mean age of 52.3 years. The predominant clinical presentation was maculopapular exanthema (77.8%), mainly involving the scalp. Mean time to HSR was 3 days post-infusion, during the second chemotherapy cycle. All patients received 3-7 days of post-medication; 7 of them tolerated the new administration of the drug, while the other 2 underwent a 3-bag, 12-step desensitization. Conclusions: Delayed drug hypersensitivity reactions (DHRs) are a T cell-mediated immune response that occur more than 6 h after exposure, leading to treatment discontinuation or alternative therapies. Management remains poorly defined; however, our findings suggest that pre-medication and RDD may safely support continued chemotherapy. To our knowledge, this is the most extensive reported series of taxane-related DHRs managed with post-medication and RDD in Hispanic population phenotype.