The Project Runway beauty reveals she recently received the bad news in a phone call from a nurse at one of her daughter's schools, and quickly discovered her other three kids' were infested with head lice.

The panicked mum, who was at work at the time, asked her hair stylists to give her a quick check for lice, and was relieved when they told her she was bug free, but hours later assistants she had tasked with treating her kids' hair found Klum had been walking around with lice and eggs in her hair too.

She explains, "I'm at work (with my) hairdresser (and) I said, 'Can you please check if I have lice?' They're looking and looking and they're like, 'No, no, no, everything is fine', so I'm like, 'Great!'

"All four of my children, they're at home, they're all being picked... In all these years, that has never happened. It's a nightmare! You have to wash everything. And then I come home and I sit down and the lice fairies (assistants) look.

"Sure enough, (I'm) covered in lice eggs and lice on my head. Who knows how many months I've had these already? I mean, I went to Australia to New Zealand to London to New York! I went all over the place! I took them global...! It's a mum's nightmare."