Hi there,

Because I'm laid up now with neuropathic symptoms (dysautonomia), I have time for quick research about your case and found that flat feet can cause all sorts of problems....they can also can get precipitously worse: ie "fallen arches." Consequently, this can affect other joints and muscles...which is why you might have pain in your back and knees, etc.

My sensory neuropathy is relatively new: >year.....and is worsening relatively rapidly. I have positive skin biopsies confirming nerve damage. As far as I know I don't have an underlying autoimmune disorder. I think my pain might differ from yours .....
( you can compare)

My neuropathic pain:

- worsens suddenly at night
- is weird...sort of vibratory and electric
- I have weird sensations...now sort of like someone is pushing bristles from the inside to the outside of my skin (paresthesias)
- jumps around...top of foot, knee, shin...in minutes
- I have allodynia....sensitivity to my socks, pants, carpet as I walk...this worsens at night
- I have hair loss on my legs
- I have sensory loss (determined at neurologist.....when they poke with pins and hold a tuning fork against you)

Now your dry eye, mouth, hair and weight loss may point to sensory and/ or autonomic neuropathy...I have both...and I think you should definitely check this all out.

It still might not be autoimmune...most neuropathy is idiopathic. But see a rheumatologist to be on the safe side. Mine is most likely from medication that was neurotoxic for me.....don't know for sure. My autonomic symptoms are far more disabling than my pain now (very deregulated blood pressure and heart rate....do you have any signs of this?)

Autoimmune diseases underlying neuropathy, like Sjogrens, are far more common in women...but do occur in men.

My hope is that you are getting older and your flat feet are collapsing further...that is definitely the best case scenario! What is really difficult(as you suggest) is finding a good neurologist and a rheumatologist to work with you on this....

Please update .....!