Small fiber neuropathy (SFN) experiences

Austin Turner said:I’d actually love to keep this thread going—I have a close family member who deals with this constant burning sensation in their feet.
How do you even prove it’s actually neuropathy?

You basically need a full neurological workup—EMG, an MRI of the brain, and a color Doppler. Small fiber neuropathy (SFN) is ultimately confirmed through a biopsy, though that’s a pretty rare diagnosis to get officially cleared here in the States.

It's becoming way more common lately since it's usually the go-to lingering symptom from Long COVID.

The first step—plain and simple—is to see a neurologist.

What happens when someone carries a pre-existing diagnosis, like an F-code, and neurologists simply treat them based on that label rather than actually listening to what the patient is saying?

I’m concerned we’ll need to clear that with whoever is managing the F diagnosis first.

Hello. I just found this thread regarding this condition, so I registered an account to ask a few things.

First, I should probably explain my history and symptoms. I first felt tingling and intense pain in my legs when I kicked a soccer ball back in elementary school, more than 15 years ago (I am 29 now). I used to wonder why others could kick a ball with such force and be fine; I asked my friends if they ever felt tingling, and they said no... A year or two later, my hands started burning quite a bit whenever I walked (a skin burning sensation in the palms, almost like a burn from fire)... Over the years, various symptoms have appeared; some diminish over time, while others intensify. Currently, I am dealing with many symptoms and I find it difficult to get anything done. When I perform physical labor or exercise, I am hit pretty hard a day or two after, maybe three days after; the intensity of the symptoms seems to align with my physical activity. If I push myself too hard, the pains become more severe and last for more days. I rarely experience the tingling these past few years; mostly, it is the burning on my palms, weakness in my hands and feet (I cannot grip things tightly), and my extremities feel ice cold. I also have pain in my wrists, hands, shoulders, neck, and back; I feel best when I am lying stretched out in bed. My shoulders ache regardless when I try to do something with my arms raised (for instance, I can't paint a room; if I hold the brush up for more than 30 seconds, my arms just drop from the pain). My fingers don't work very well; I miss keys on the keyboard, and I struggle to write or draw... My memory is very poor, as is my concentration. My legs serve me better than my hands, so I can walk quite a bit. I freeze and shiver outside when the temperature drops below 60 degrees, even if I am dressed well (during those times, my skin doesn't burn, but it starts to burn intensely in the heat once my hands warm up). A strange symptom that might not be related, but perhaps is linked to the cause—I am allergic to the sun; after being out too long, I get a rash, the itching is unbearable, and my skin turns red and white (it isn't a typical sunburn). For years, doctors tried to dismiss my symptoms as psychological, much like they did for many others, even though the symptoms are always present and not just during periods of anxiety. Maybe two years ago, a neurologist gave me a diagnosis of idiopathic neuropathy; that was the first time I had heard of it. I took pregabalin for three months; it felt better for the first two weeks, but then things worsened, so I stopped. Before that, I took piles of different medications; I forget what they all were. I had an EMG, which was negative, then I learned about small fiber neuropathy, SFN, since I suppose it is one of those rare types among 300 neuropathies where the EMG comes back negative. I have undergone various tests over the years; I don't have any of the well-known autoimmune diseases. In my bloodwork, my platelet count is just near the lower limit, and my bilirubin was elevated, though that was likely due to gallstones, which I had removed a month ago...

My question is this. Since some members mentioned that in Washington, D.C. one can undergo a skin biopsy to check for SFN, which a neurologist from Nashville also mentioned to me, which clinic offers this? Has anyone here done it? Biopsies are available at various clinics, but I suppose most don't check those specific fibers; most probably just check for skin diseases, fungi, etc.

Andrew Miller87 said:Hi. I just stumbled upon this thread regarding this condition, so I registered just to ask a few things.

First, let me lay out my history and symptoms. The first time I felt tingling and intense pain in my legs was back in elementary school when I kicked a soccer ball—that was over 15 years ago (I'm 29 now). I remember wondering why the other kids could kick a ball with everything they had and feel nothing; I asked my buddies if they felt tingling too, and the answer was no... A year or two later, my hands started burning quite a bit whenever I walked (a burning sensation on the skin of my palms, almost like a thermal burn)... Over the years, various symptoms have cropped up—some fade over time, others intensify. Right now, I’m dealing with enough symptoms to make it hard to function. When I work a physical job or train, it hits me hard a day or two afterward—the intensity of the symptoms seems directly tied to my physical activity level. If I push myself too much, the pain gets worse and lasts longer. I rarely get the tingling these days; mostly, it's the burning on my hands, weakness in my hands and feet (I can't grip things tightly), extremities that are ice-cold, and pain in my joints, hands, shoulders, neck, and back. I find the most relief when I’m just "flopped" in bed... My shoulders also kill me generally whenever I do anything with my arms raised (for example, I can't paint a room; if I hold the brush up for more than 30 seconds, my arms just give out from the pain). My fingers don't cooperate well either—I miss keys on the keyboard, and I struggle with writing or drawing... My memory and concentration are also pretty terrible. My legs serve me better than my hands, so I can walk quite a bit. I freeze and shiver outdoors whenever the temperature drops below 55 degrees, even if I'm dressed well (the burning sensation isn't there then, but once my hands warm up in the heat, the burning starts again). One strange symptom that might or might not be related to the root cause is that I'm allergic to the sun; after being out too long, I get a rash, the itching is unbearable, and my skin turns red and white (not your typical sunburn). For years, doctors tried to write my symptoms off as psychological, just like they did with many others, even though the symptoms are always present and not just during times of anxiety. About two years ago, a neurologist gave me a diagnosis of idiopathic neuropathy—that was the first time I'd even heard of it. I took pregabalin for three months; I felt better for the first two weeks, but then things worsened, so I quit. Before that, I went through a mountain of different medications, and I honestly forget what they all were. I had an EMG, which came back negative, then I learned about small fiber neuropathy (SFN), since apparently, it's one of those rare cases among hundreds where the EMG shows nothing. I've run all sorts of tests over the years, and I don't have any of the well-known autoimmune diseases. In my bloodwork, my platelet count is right at the lower limit, and my bilirubin was elevated, though that was likely due to gallstones, which I had removed a month ago...

My question is this: Since some members mentioned that you can get a skin biopsy in Washington, D.C. to check for SFN—which one of my neurologists in Nashville also mentioned—which clinic actually performs this? Has anyone here done it? There are biopsies available in various clinics, but not all of them actually test those specific fibers; most seem to only look for skin diseases, fungi, etc.

Hey Andrew Miller87
I have a lot of similar symptoms. I don't know what else it could be—small fiber neuropathy, erythromelalgia (since I get redness in my palms and soles sometimes), Raynaud's syndrome (because my feet are freezing all winter), POTS... It all feels like the same thing.
Since my diagnosis, I've had erythromelalgia, and a dermatologist told me there isn't much help for it, which is true. I also have a diagnosis of joint hypermobility; I personally believe it's actually hypermobile Ehlers-Danlos syndrome, which isn't really talked about much here and isn't treated anywhere—they just treat the symptoms. All of this other stuff could very well stem from that.
As for skin biopsies—I don’t personally know anyone who’s gone through it, but I heard from someone a few years back that you can get it done at a major university hospital like Johns Hopkins... though you need a formal referral first. And honestly, how are you supposed to secure a referral when half the neurologists and GPs out there haven't even heard of small fiber neuropathy? It's a joke.
Where are you located? It sounds like we might be in the same neck of the woods—assuming you're near Nashville.

I'll shoot you a DM.