Near-fatal anaphylaxis to patent blue V

Abstract

Rationale Coloring with patent blue V is a standard method in identifying the draining sentinel lymph node in melanoma skin cancer and breast cancer patients. We describe a case of anaphylaxis with 10 minutes cardiac arrest requiring mechanic cardio-pulmonary reanimation measures after the intradermal administration of patent blue V in a melanoma patient. The patients survived the incident without any sequelae. Methods One month after the incident, in vitro (RAST, total IgE, serum tryptase, ELISA for IgE binding to patent blue V) as well as in vivo (prick and intradermal skin test) tests were performed. Results A positive intradermal test to patent blue V and the patent blue derivative isosulfan blue at a dilution of 1:10000 confirmed the specificity of the anaphylactic reaction. While an experimental RAST revealed normal values, there was a high IgE signal to patent blue V and isosulfan blue in an experimental ELISA system. Sera from healthy controls showed only low signal intensity. Other allergies were excluded based on negative history, skin and standard in vitro tests. Conclusions To our knowledge, this is the first demonstration of IgE binding in a very severe case of anaphylaxis to patent blue V.