The 31-year-old was forced to pull out of a promotional appearance for her book Beautiful Ever After.
It comes after Katie missed her daughter's first birthday party because she was in hospital.
Taking to Twitter to break the news, Katie wrote: "So sorry to have to pull out of tonight.
"I am incredibly frustrated as I hate it when my injuries get in the way of everyday life. I'm very ill.
"Just want to try and find a way forward to get back to normal health."
In 2008 Katie suffered a horrific acid attack which left her severely burned and scared.
Katie missed Belle's party earlier this month after reported complications during an operation.
Tweeting on the day of the party, Katie said: "Thanks for all the birthday tweets for Belle!
"Unfortunately I'm in hospital but her dad tells me she's had a lovely day."