Threadworms question (there's no grim details!)

[coffeepleeease]

DD (5) has been itching her vagina and more so at night for months now. I've assumed it was from wearing a pull up at night (not dry overnight yet), as she doesn't itch much or at all in the day. Been putting nappy cream on occasionally. Just entered my head that it could be threadworms Could it be threadworms if they're not in her poo? TMI but I inspect her poo every time she goes as she suffers with chronic constipation so keep track of if it is hard/soft. Never seen any worms. I know the only way to know for sure is to check her bum at night but she's such a light sleeper and slightly traumatised from having many suppositories is it likely she'd have had them all this time without them being in her poo, and nobody else in the household having symptoms?

I honestly don't know, but know it's possibly for them to pass to the vagina. I would expect them in the anus and bowels too though. I'd give her a tablet just in case. And check for thrush.