Thanks again Mrs D
Although I had some symptoms of PN prior to an emergency appendectomy in Oct 2014, I was wondering why it had suddenly increased and spread over my entire body since. Have just checked the medical notes from the surgery and found I was given Metronidazole while in hospital, (first time taking it). Yet another possible cause to mention to the neuro when I finally get an appt. With the amount of info I've learned from this site I'll need to be careful not to annoy the doctor - especially if he gives a diagnosis of idiopathic PN - which from what I've read here seems to be the answer they give when they either don't know or can't be bothered looking further.