Allergic reactions to isosulfan blue during sentinel node biopsy - a common event

Background. Sentinel lymph node (SLN) dissection in the management of high- risk melanoma and other cancers, such as breast cancer, has recently increa sed in use. The procedure identifies an SLN by intradermal or intraparenchy mal injection of an isosulfan blue dye, a radiocolloid, or both around die primary malignancy. Methods. At the time of selective SLN mapping, 3 to 5 mL of isosulfan blue was injected either intradermally or intraparenchymally around the primary malignancy. From October 1997 to May 2000, 267 patients undo-went intraoper ative lymphatic mapping with the use of both isosulfan 1 % blue dye and rad iocolloid injection. Five cases with adverse reactions to isosulfan blue we re reviewed. Results. We report 2 cases of anaphylaxis and 3 cases of "blue hives" after injection with isosulfan blue of 267 patients who had intraoperative lymph atic mapping by the procedure described above. The 2 patients with anaphyla xis experienced cardiovascular collapse, erythema, perioral edema, urticari a, and uvular edema. The blue hives in 3 patients resolved and transformed to blue patches during the course of the procedures. Conclusions. The incidence of allergic reactions in our series was 2.0 %. A s physicians expand the role of SLAT mapping, they should consider the use of histamine blockers as prophylaxis and have emergency treatment readily a vailable to treat the life-threatening complication of anaphylactic reactio n.