--get a good rheumatology consult, as there are many peripheral neuropathies that are autoimmune in origin. Be judicious, though--a lot of rheumies are only familiar with the ant-nuclear antibody (ANA) mediated collagen/connective tissue/vascular conditons (i.e, Sjogren's, lupus, polyarteritis nodosa, etc.) and not as familiar with atuoimmune conditions such as celiac or other conditions in which antibodiea re produced that are specific to peripheral nerve components:

http://neuromuscular.wustl.edu/antibody/pnimdem.html

http://neuromuscular.wustl.edu/antibody/pnimax.html

And that cervical spine consult is a good idea as well. One of the most annoying things about peripheral nerve symptoms is that they can be exactly mimicked by problems in the spinal cord or spinal nerve roots, even at the cervical level (which can affect any part of the body at or below that level, inclduing the legs/feet); the investigation into potential causes is often one of long investigation and process of elimination, if a direct cause is even findable.