I think that your next move needs to be:
a) get backing from physician to keep child out of school until communication issue is resolved (re: safety, basically)
b) cc: nurse, IEP coord, and princ. about your child's absence, and
c) request classroom work for the next couple of weeks-- so that your child is not harmed academically by this unresolved set of communication issues.
Then Bcc: that to the vice-super along with everything else.
This (strategically) does several things. It demonstrates that you are a "team player" in that you are being cordial and cooperative with everyone involved, you are trying to do what others have asked of you, and that your child's safety and academics are your major concern, not scoring hit-points or anything else. It also makes it clear just how bizarre the principal is being here-- because s/he will probably respond with more "crazy" to it-- maybe you won't be allowed to contact the nurse, either, anymore. Which you will then forward to the vice-super.
