Diagnosing Small Fiber Neuropathy

Diagnoising small fiber neuropathy with skin punch biopsy

You’ve probably been hearing and reading more about small fiber neuropathy. Doctors can now make the diagnosis in their office, by doing a 3 mm skin punch biopsy and sending the specimen to Therapath for determination of epidermal nerve fiber density. The procedure takes only 5 to 10 minutes to perform, there is little discomfort to the patient, and the biopsy site is covered by a band aid. The test is most useful in patients with symptoms or signs of neuropathy, who’s electrodiagnostic studies don’t show any abnormalities, as is the case in small fiber neuropathy.

Therapath is a company that offers expert, comprehensive and prompt neuropathology services, specifically muscle, nerve, epidermal nerve fiber, sweat gland nerve fiber and brain, tissue analysis (or studies) to hospitals, private practitioners, reference laboratories, pharmaceutical industry, and researchers throughout the United States and Canada (abroad).

The company is accredited by the American College of Pathology (CAP) and has an established reputation of offering quality specialized neuropathology services that most major teaching institutions are cutting back on, rather than growing into. Our medical directors are board certified in neuropathology.

Neuropathology and Neuromuscular Pathology services are available for both clinical and pre-clinical investigations of potential therapeutic agents, drug toxicity, and of nerve or muscle regeneration. The company has the ability to scale up from proof of concept studies to multiple centers Phase II/III trials.

The specific tests Therapath performs are:

1. Muscle biopsy studies: including routine histology, immunohistochemistry and enzyme histology, for diagnosis of muscular dystrophies, inflammatory myopathies such as dermatomyositis or Polymyositis, or other metabolic, toxic, or inherited muscle diseases and Electron Microscopy.

2. Nerve biopsy studies: including routine histology, teased fiber analysis, and immunohistochemistry for diagnosis of CIDP, vasculitic, demyelinating neuropathies, sarcoid or amyloid neuropathy and Electron Microscopy.

3. Skin biopsy studies for Epidermal Nerve Fiber Density and Sweat Gland Nerve Fiber Analysis.

4. Consultation:

• Brain and spinal cord tumor biopsy and resection specimens

• Non-neoplastic brain and spinal cord biopsy specimens

• Brain and spinal cord autopsy specimens, including dementias


• Licensed under CLIA (Clinical Laboratory Improvement Amendments)

• The Centers for Medicare & Medicaid Services (CMS) regulates all laboratory testing (except research) performed on humans in the U.S. through the Clinical Laboratory Improvement Amendments (CLIA). In total, CLIA covers approximately 225,000 laboratory entities.

• The CAP (College of American Pathologists) Laboratory Accreditation Program is an internationally recognized program. An accredited laboratory is one that is inspected by a private not-for-profit t accrediting organization and the laboratory has met the highest standards of excellence.

CONTACT Information:
545 West 45th Street
New York, New York 10036
Phone: 800-681-4338
to Visit the Therapath Web Site Click Here:

About the Author

LtCol Eugene B Richardson, USA (Retired) BA, MDiv, EdM, MS

Col Richardson has suffered with severe neuropathy for over 45 years. A 27 year military veteran and veteran of the Vietnam War, he was diagnosed with a progressive chronic peripheral neuropathy resulting in severe disability. This diagnosis has been confirmed as due to exposure to Agent Orange. It was not until 2010, 42 years after his exposure to Agent Orange, that his diagnosis was recognized by Veterans Affairs as service connected.

Author Archive Page


  1. Dear Col Richardson,
    Thank you for your service, and thank you for this website and the ability to comment and receive answers from you on various topics. I thought I had posted my question yesterday, but I don’t know if it went through, if it did, please forgive me for duplication.

    I have been dealing with neuropathic pain in arms, legs, hands and feet since 2006, after sustaining a TBI in a bicycle accident. It has not gone away…..Many tests were done in the first few years but nothing was conclusive per my doctor…..and I have had other health issues co-occurring (chronic pain issues due to carpal and cubital tunnel syndrome, arthritis in entire spine/knees/shoulders/foot, chronic headache, TMJ, tendonitis that wont resolve, etc) however, I was just looking back at old records on a patient portal site and came across a skin punch biopsy report from 2007 with findings that I have no recollection of my doctor (who I no longer see) providing to me, my PCP doesn’t remember receiving this either. The report reads:

    Morphometric quantitation of PGP9.5 immunolabeled epidermal nerve endings
    yielded a density of 415 neurites per square mm of skin surface area, at the
    91st centile for age, far above the normal range. Fragmentation of axons can
    contribute to unusually high numbers of neurites. The clinical significance of
    increased neurite counts has not been defined in the medical literature,
    although clinical experience links it with early axonopathy. This density can
    be monitored with future biopsies to evaluate disease progression or the
    effects of therapy.

    I would love to know your thoughts on this test result. Was this test result POSITIVE for Small Fiber Neuropathy? I cannot find anything in my online research for AXONOPATHY (indicated in test result verbiage).

    Thank you so much for your insight and assistance,

    1. Sandra: Our medical texts note that this test report is positive for neuropathy but they usually note a small fiber neuropathy and axonopathy means that it shows damage to the actual nerve or axon rather than to the myelin covering of the nerve. We recommend skin biopsy be done by this firm as they are very reliable. Please see the information at this article and if you want the skin biopsy to rule out SFN give the information to your doctor: Skin Biopsy for diagnosis of small fiber neuropathy http://neuropathyjournal.org/skin-biopsy/ In addition SFN if diagnosed is often treatable with IVIg as noted by an expert on the subject. I will send you an E mail direct with a copy of the article on IVIg for SFN.

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