Leucovorin-induced hypersensitivity reaction.

Leucovorin is a reduced form of folic acid, which has multiple uses.(1) In this case report, it is used in combination with fluorouracil in the treatment of colon cancer. We describe a 53-year-old male, who was started on FOLFOX 6 + bevacizumab who experienced a hypersensitivity reaction to leucovorin. There have been very few cases of leucovorin hypersensitivity reactions reported in the literature. In this case, symptoms include flushing, hives, body pain, headaches, elevated blood pressures, and general discomfort. Although leucovorin reactions are considered rare, one should be aware of the types of reactions that can occur with leucovorin.