AceShowbiz - Actress Olivia Munn had to leave the 2018 Met Ball just moments after wowing on the red carpet because her metal headpiece gave her a nasty rash.

The X-Men: Apocalypse beauty looked stunning in gold from head to toe at the high-profile New York City fashion gala, wearing a chainmail H&M dress and matching head covering by designer Michael Schmidt as she arrived at the Metropolitan Museum of Art, where the theme of the night was Heavenly Bodies: Fashion and the Catholic Imagination.

Olivia, who drew inspiration from The Crusades for her warrior style, had initially been concerned she wouldn't be able to dance in the intricate gown, especially as she had to be stitched into the outfit, but that was the least of her worries as the material started to irritate her scalp.

The star reveals she didn't tell anyone about her predicament, and instead decided to make a quick exit to ease her pain.

"It (the dress) was very heavy, but I actually left the Met Ball before dinner was served, because my metal headpiece gave me a rash on my scalp, and then started cutting my forehead!," she confessed on breakfast show Good Morning America on Monday, May 28. "I was like, 'I have to go, I'm itching, I'm bleeding'".

Olivia's night only got more interesting as she was waiting for her driver, as she almost got into the wrong vehicle, which had been hired by Katy Perry specifically to transport the giant angel wings she worn on the red carpet.

"I was actually outside and waiting for my van to come and I went to go walk to this van, and the man (driver) goes, 'No no, I'm just here for the wings,'" she recalled. "I'm like, 'The wings?' Oh yeah, Katy Perry's wings...!.

"People have a wing man, she has a wing van...! It was amazing!".