Anaphylactic response to blue dye during sentinel lymph node biopsy

The sentinel lymph node (SLN) procedure is now used routinely for the staging of clinically node-negative patients with early breast cancer. Two identification techniques exist: colorimetric and isotopic. These can be used alone or in combination. The combined method is associated with an increased identification rate. However, allergic and adverse reactions to blue dyes have been reported. The objective of this review was to determine the incidence of such events and to discuss alternative approaches. The authors conducted a search of the MEDLINE and EMBASE databases for reports of anaphylactic responses to isosulfan blue dye and patent blue V dye. Allergic reaction to the dyes isosulfan blue and patent blue V is rare and the reported incidence varies between 0.07% and 2.7%. Methylene blue dye appears to be safer, with no cases of allergic events having been reported. However, allergy tests in some patients have proven that there is cross-reactivity between isosulfan blue dye and methylene blue dye. Even though the risk of an anaphylactic response is low, this raises questions about the usefulness of colorimetric detection of SLN and whether alternatives to the use of the isosulfan and patent blue V dyes, such as methylene blue, exist.