The singer canceled her Bangerz tour appearance scheduled for Tuesday at the Kansas City Sprint Center.
"Cyrus has been hospitalized for a severe allergic reaction to antibiotics and has been placed on medical rest by her doctors," according to a statement from the Sprint Center.
Cyrus, 21, Tweeted a statement of apology Tuesday evening.
"Kansas I promise I'm as [heartbroken] as you are. I wanted so badly 2 b there 2night. Not being with yall makes me feel s––––––– than I already do," she wrote.
Cyrus also canceled her Charlotte, N.C. tour stop just over a week ago after she was "diagnosed with the flu and doctors have ordered her to rest," Live Nation says.
Mr. Octopussy & some amazing Drs are taking good care of me pic.twitter.com/7FJFxYa7M5— Miley Ray Cyrus (@MileyCyrus) April 15, 2014