Talk to Pediatrician on Hypertension?

What reassurance can be offered to a child before a complete routine physical examination, considering the fact that the child’s blood pressure shoots to 190/100 or 200/100 during her visit to the doctor’s office? It is suggested that her blood pressure is probably always a little high and becomes even higher when she feels threatened by the doctor’s presence. Is there any way this can be confirmed? The child is not willing to submit herself to well-child check ups anymore. What reassurance can be offered before a well-child exam? (There are no noticeable symptoms and signs of any disease, except high blood pressure, irregular heart rhythm and complaints of severe headache at the doctor’s office.)