Flagship Specialty
ENFD Testing.
The Gold-Standard in small fiber neuropathy diagnosis.
A dedicated, validated, physician-first program for Epidermal Nerve Fiber Density skin biopsy interpretation.
The Overview
A validated diagnostic gateway for a hidden diagnosis.
Small fiber neuropathy affects millions of patients whose symptoms are often dismissed or misdiagnosed. Because small nerve fibers are invisible on standard nerve conduction studies, definitive diagnosis requires skin biopsy quantification of intraepidermal nerve fiber density. GoldPath's ENFD program brings validated technique, expert interpretation, and clinical clarity to every case.
Symptoms
How small fiber neuropathy presents.
Patients often see multiple specialists before receiving an accurate diagnosis. Recognizing the pattern is the first step.
Burning or scalding sensations
Sharp, electric, or shooting pain
Numbness and tingling
Altered temperature perception
Allodynia — pain from light touch
Autonomic dysfunction
Why ENFD Matters
The most sensitive and specific test available.
Skin biopsy ENFD outperforms every other clinical or electrodiagnostic method for confirming small fiber neuropathy.
Diagnostic Sensitivity
Diagnostic Specificity
Typical Turnaround
Clinical Indications
When ENFD testing
changes the answer.
Consider ENFD skin biopsy when standard workup is inconclusive, when nerve conduction studies are normal despite ongoing symptoms, or when small fiber involvement is suspected in a systemic disease.
- Idiopathic small fiber neuropathy
- Diabetes mellitus
- Sjögren's syndrome
- Sarcoidosis
- Amyloidosis
- Fabry disease
- Celiac disease
- HIV
- Post-viral / post-COVID neuropathy
- Chemotherapy-induced neuropathy
- Autoimmune small fiber neuropathy
- Chronic idiopathic pain syndromes
The Science
PGP 9.5 immunostaining meets validated normative data.
GoldPath's ENFD workflow uses protein gene product 9.5 (PGP 9.5) immunohistochemistry to visualize small unmyelinated nerve fibers crossing the dermal-epidermal junction. Fibers are counted by trained pathologists across multiple sections and compared to age-, sex-, and site-matched reference ranges to generate a defensible, clinically actionable diagnosis.
Collection Process
From biopsy to report in five steps.
Our workflow is designed to feel effortless for your practice and rigorous for your patient.
01
Request a kit
Order pre-assembled 3-mm punch biopsy kits with fixative, instructions, and prepaid return shipping.
02
Collect the biopsy
Perform standard 3-mm punch biopsies at distal leg, distal thigh, and optional proximal thigh sites.
03
Overnight to GoldPath
Return specimens using included shipper. Samples enter processing the day they arrive.
04
Expert interpretation
Board-certified pathologists perform PGP 9.5 immunostain quantification against site-matched normative data.
05
Physician-ready report
Clear, clinician-focused report delivered digitally — with direct pathologist access for any question.
Reporting
Reports built for clinicians, not for archives.
- Clear diagnostic conclusion at the top of every report.
- Site-matched ENFD counts with normative comparison chart.
- Representative digital images embedded in the PDF.
- Interpretive commentary tailored to the clinical question.
- Direct pathologist contact for follow-up discussion.
Why GoldPath for ENFD
Everything a validated program should be. Nothing it shouldn't.
Downloads
Everything your practice needs.
Frequently Asked Questions
ENFD, answered.
Request a Kit
Order your first ENFD kit today.
Complimentary pre-assembled biopsy kits ship overnight to your practice. No account setup required.
Kit Request
We'll follow up within one business day to confirm shipment.
Physician Support
Prefer to talk to a
pathologist first?
Our pathologists welcome direct clinical conversations before you send a single specimen.