Reynolds' publicist Kevin Sasaki says the singer-actress was hospitalized in Los Angeles after having the bad reaction. She is canceling shows and appearances through the end of the year.
Reynolds is famous for her role in "Singin' in the Rain" and earned an Oscar nomination for her gutsy character in "The Unsinkable Molly Brown."
The 80-year-old performs numerous shows and makes appearances each year. She is scheduled to appear on a float promoting pet adoption in the upcoming Rose Parade.
Last year, Reynolds sold her collection of film memorabilia, including dresses worn by Marilyn Monroe and Audrey Hepburn, for nearly $23 million.