The baby girl has itching in her rear passage. It's 4 am now, we are…

The baby girl has itching in her rear passage. It's 4 am now, we are sitting on the internet with my husband, from what could it be? They write about worms. I'm not sure, but I think it might be possible. The baby also wants to sleep, but can't because of itching. We turned on a cartoon, she yawns and sometimes tries to scratch, but can't reach with her hands, and we with my husband turn around and scratch clean hands. The baby will be six months old this month. Has anyone encountered something similar? Please advise something, I would be very grateful ??