The 35-year-old actress stepped down from the role of Kate Kane and her titular alter ego in May 2020 after just one season of The CW show and now she has explained how the character's costume played a big role in her decision.
Appearing on Australia's "The Kyle and Jackie O Show", she said, "I did find out that I was allergic to latex... and unfortunately my mask is latex. I was like, 'I'm a little itchy!' And it was getting worse and worse, because as you get more contact with it, I guess you get more reactions."
"I took (it) off at the end and my whole face was just hives."
Last year, Ruby had opened up on her decision to leave the show, which she said at the time was partly influenced by the coronavirus pandemic.
"I think what played a bigger part was more, we got shut down early," she said. "We didn't get to finish the first season, which is such a shame, especially for a first season show … and then we went into lockdown with Covid and thinking of (being) in quarantine and locked down, there was a lot of thought and reflection and kind of everyone did it."
"You know, we all kind of thought about where we're at … we were discussing the show and we had a conversation. We did have a discussion and we sort of mutually agreed that probably what was best for the show at the time was they go in a different direction and I go in a different direction."
For the second season, Kate Kane was written out of the show and replaced by Ryan Wilder, who was played by Javicia Leslie, before the role of Batwoman was recast and British actress Wallis Day was announced as the new female caped crusader in March (21).