Most sore throats are caused by colds, the flu, coxsackie virus or mono (mononucleosis). Bacteria that can cause pharyngitis in some cases: 1  Strep throat is caused by group A streptococcus.  Less commonly, bacterial diseases such as gonorrhea and chlamydia can cause sore throat.
To call for an appointment at Mayo Clinic in Rochester, Minnesota simply call 1-507-284-2111 and a friendly Mayo Clinic person will patiently answer all your questions, guide you through the process, and make your appointment.
I would call the Mayo Clinic or call your insurance company. Your ins. co. should be able to tell you if they will require a referral. Mayo Clinic will also be able to tell you all the requirements for getting in there. I think you can also have them just do a records review and second opinion without having to actually go there if you wanted to do that.