The big question - do you exclude?

I am VERY good friends with the head teacher at my sons school and care for her children on staff training days. We talk about all sorts and she's just been telling me about the things she's had to do recently. Change the Disability policy etc because it's changing to equality, but the one that got me most confused is lice - she says she's now allowed to exclude!! Apparently, there was a case a few months back of a mother who refused to treat her child because "the child would just get them again off another child anyway, so it was a waste of time". It became such a problem with the child itching and creating sores on her head that the insects got under her scalp and she got REALLY ill. It's now safeguarding issue according to the head.

Anybody else heard of this? x