Hypersensitivity reactions to Patent Blue V in breast cancer surgery: a prospective multicentre study.

An increasing number of immediate hypersensitivity reactions (HSR) have been reported after the use of Patent Blue V (PBV) for breast cancer surgery. This is the first study to publish prospective data with systematic allergological assessment. We conducted a multicentre study in 10 French cancer centres for over 6 months. All patients scheduled for breast surgery with injection of PBV were included in the study. Patients were screened for past medical history, atopy, and known food and drug allergies. When suspected HSR or unexplained reactions occurred after injection of PBV, blood samples were taken, and plasma histamine and serum tryptase concentrations were measured. HSR to PBV was suggested if skin tests performed 6 weeks later were positive. Nine suspected HSR to PBV were observed in 1742 patients. Skin tests were positive in six patients, giving an incidence of 0.34%. Four grade I and two grade III HSR were observed, both requiring intensive care unit treatment. Mean onset time of the reaction was 55 ± 37 min. Plasma histamine was elevated in four patients, while serum tryptase was normal. We found no risk factors associated with HSR to PBV. An incidence rate of one in 300 HSR to PBV was observed for patients exposed to PBV during sentinel lymph node detection. This rate is higher than rates reported after the use of neuromuscular blocking agents, latex or antibiotics.