Burning mouth, including the gums are common in PN. Peripheral does not refer to the location only to the fact that the neural tissue involved is not the spinal cord, or brain. Peripheral nerves innervate your stomach, intestines, heart, etc. Peripheral nerves are everywhere in your body, but the spinal cord and brain. I can best compare them to the capillaries of the vascular system. I experience burning in my mouth off and on and have for a decade.

It is also not uncommon for those with PN to have their lacrimal glands and salivary glands denervate, resulting in neurologically induced dry eyes and dry mouth, this is not to be confused with the autoimmune disease of Sjogren's Syndrome. Biopsies of the salivary glands in the lip of Sjogren's Syndrome patients will show inflammatory infiltrates, which will not appear in the neurological sicca syndrome.

Oh, and the tongue can also burn, and it can occassionally be quite bad. If you ask your dentist, he/she will probably tell you, that you are fine....actually, my tongue burning badly was really one of my first real clues that this was small fiber neuropathy. It took 5 more years to diagnosis.