WOW! I am shocked and appauled that a teacher would be so lackidasickle about something so very important to you, your husband and espcially to your child when he goes to the doctor.
I do not think that you are over-reacting, this is your child! Your number one concern, priority, and love of your life, needs help and this teacher is treating it like it is "not worthy of her full attention and time".
If it were me, and this were happening to my child, I would have a meeting with the principal at the school without the teacher first, then ask that the teacher be brought in to explain herself to the principal/her superior. And if this doesn't get you anywhere go to the school board and speak with someone there...this to me is a very serious issue and could cause a misdiagnosis for your son. And could cause very bad reprecussion if he were to be put on the wrong meds, just because she is being lazy, inconsiderate, and unprofessional.
If you don't get satisfaction from the school board (she needs some form of written reprimand in her file for this!) then I would go to the television stations and ask to tell your story but keep your identity hidden if you don't want others to know who you are!
Just my humble opinion, I am very passionate when it comes to my child and from your post, it seems that you are too!
Best of luck to you sweetie and let me know how it goes or what you decide,
Julie Lynn
Lexington Ky
www.lexingtongotogirl.blogspot.com