Anaphylactic reactions to 5-fluorouracil (5-FU) are uncommon. We report a 4
0-year-old female with adenocarcinoma of the ovary who had two reactions im
mediately after being infused with 5-FU. The second reaction occurred despi
te prophylaxis with steroids and antihistamines. The patient was positive t
o 5-FU on puncture skin testing even though there was no previous exposure
to the drug. We successfully desensitized her to 5-FU using a continuous in
travenous protocol with sequential increments in the fusion rates and drug
concentrations. This desensitization method may be useful to manage systemi
c reactions to 5-FU and other drugs.