I too sometimes used to have a metallic taste in my mouth, this was however before I found out that I was type 2, I put it down to an allergy, as my face used to swell up too, but there again since it has been under control, I dont seem to have a problem. It would seem that the endocrine system is very complicated and different things affect people in different ways. Doctors well some think that they know an awful lot but medicine is an art and a science.
regards