Perioperative hypersensitivity reactions to Patent Blue V in sentinel lymph node biopsy for breast cancer and melanoma

POH to PBV is rare but clinically significant, with a rate of 0.2% in breast cancer SLNBs and 0% in melanoma SLNBs, though this difference was not statistically significant in our study. Variations in PBV administration techniques between breast and plastic surgeons may contribute to the different rates. In five patients with confirmed POH to PBV symptoms consisted mainly of mucocutaneous signs and hypotension. Awareness of these rare but potentially life-threatening reactions, along with prompt management, is essential for both surgeons and anaesthesiologists. This study further underscores the importance of vigilant perioperative monitoring and formal allergy evaluation to guide future care.