Breast cancer dye allergy testing
Breast cancer dye allergy testing for isosulfan blue
Isosulfan blue is a dye commonly used in sentinel lymph node biopsies in patients with breast cancer. Approximately 1 to 3% of patients have allergic reactions to this dye.
The chemical name of Lymphazurin 1% (isosulfan blue) is N-[4- [[4-(diethylamino)phenyl] (2,5-disulfophenyl) methylene]-2,5- cyclohexadien-1-ylidene]-N-ethylethanaminium hydroxide, inner salt, sodium salt. Its structural formula is:
Sentinel lymph node (SLN) dissection in the management of high-risk melanoma and other cancers, such as breast cancer, has recently increased in use. The procedure identifies an SLN by intradermal or intraparenchymal injection of an isosulfan blue dye, a radiocolloid, or both around the primary malignancy. (Surgery. 2001 Sep;130(3):439-42.)
Outpatient testing involves a skin prick test (SPT) with a 1:10 dilution of isosulfan blue and with full-strength isosulfan blue and an intradermal test (IDT) with a 1:1,000 dilution of isosulfan blue, a 1:100 dilution of isosulfan blue, and a 1:10 dilution of isosulfan blue. All test results were interpreted at 15 minutes.
Breast cancer dye allergy testing protocol was tried in three patients who had reaction to this medication during breast cancer surgery. Two patients had positive SPT reactions to full-strength isosulfan blue, and one patient had a positive IDT reaction to a 1:100 dilution. None of the patients developed adverse reactions to testing.
The team then went on to examine the approach in five healthy controls. There were no positive results to the IDT at concentrations as high as 1:10.