What is Small Fiber Neuropathy?

Small fiber neuropathy is a condition that affects thousands of people, many of whom are unaware of their condition.

Small fiber neuropathy begins when the immune system attacks the small nerves in the skin, also known as the sensory nerves. As the condition worsens, sensory nerve damage can cause extreme pain and discomfort in the extremities and even make its way to other areas of the body.

Picture your body and nerve network like a tree: your body as the trunk and your nerves as the branches extending from it. With small fiber neuropathy, the nerves furthest away from the trunk are affected first.

What Causes Small Fiber Neuropathy?

If you’ve been diagnosed with SFN, an underlying cause can be identified more than 50% of the time.

These causes include:

  • Pre-Diabetes,
  • Diabetes,
  • Celiac Disease,
  • B12 deficiency,
  • Alcoholism,
  • Neurotoxic drug exposure,
  • Lupus,
  • Sj̈ögren’s syndrome,
  • Sarcoidosis,
  • HIV, and
  • Paraneoplastic syndrome.

Pre-diabetes and diabetes are the most common causes of small fiber neuropathy, making up approximately 30% of known cases and believed to make up 50% of idiopathic cases.

What are the Symptoms of Small Fiber Neuropathy?

Patients with SFN typically have numbness, tingling and pain. Pain, a prominent symptom, often comes with a burning sensation.eople with small fiber neuropathy may also experience:

  • Loss of feeling in hands and feet (or a “Pins and Needles” sensation).
  • Cramping in the hands, feet, and calves.

When nerves of the autonomic system are affected (autonomic neuropathy) a person may experience symptoms of:

  • Dizziness
  • Bowel and bladder dysfunction
  • Inability to sweat
  • Skin discoloration

How is Small Fiber Neuropathy Diagnosed?

An accurate diagnosis of SFN is possible. One or more small skin biopsies are taken from specific locations of the body. A specialized pathologist analyzes the skin sample’s nerve count (epidermal nerve fiber density) and observes  the health of the nerves to determine if the condition is present. Once a diagnosis is officially made, the correct treatment can begin.

How is Small Fiber Neuropathy Treated?

The first step in treating small fiber neuropathy is to identify  the root cause of the condition.  Once the cause has been determined, aggressive treatment follows to halt or slow the progression of SFN. The second step is to manage the pain associated with SFN. With a root cause like diabetes or pre-diabetes, physicians may attempt to control the patient’s blood sugar levels as well as prescribing neuropathic pain medications. Patients are advised to seek additional treatment, as appropriate, for the root cause(s) of their SFN.

The first step to managing small fiber neuropathy is an accurate diagnosis. Specialized labs today are able to confirm the condition using only a small skin sample. Not all doctors offer this specialized testing. To connect with an appropriate doctor, please call 855-CRL-LABS.

Additional links:

Who is Corinthian Reference Lab?


What to do with a positive biopsy?


Article links:

What is Small Fiber Neuropathy?



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