Epidermal Nerve Fiber Density Test – Biopsy Sites
Standard Biopsy sites for ENFD Testing
Therapath has established five standard biopsy sites for Epidermal Nerve Fiber Density (ENFD) and Sweat Gland Nerve Fiber Density (SGNFD). These sites allow for the diagnosis of a Small Fiber Neuropathy affecting either the upper or lower extremities in patients 18 and older.
The standard sites include the Proximal Arm, Distal Arm, Thigh, Distal Leg, and Foot. More details are available on our biopsy procedure guide.
The Epidermal Nerve Fiber Density (ENFD) test measures the density of the small sensory nerve fibers in the skin, and the Sweat Gland Nerve Fiber Density (SGNFD) test measures the density of the small autonomic nerve fibers in the sweat glands.1,2 The same biopsy sample can be used for both tests.
The skin biopsy procedure can be performed at the physician’s office and is reimbursed using CPT codes 11100 and 11101.

- Joint T. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society. J Peripher Nerv Syst. 2010;15(2):79-92. [PubMed]
- Gibbons C, Illigens B, Wang N, Freeman R. Quantification of sweat gland innervation: a clinical-pathologic correlation. Neurology. 2009;72(17):1479-1486. [PubMed]
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Abstract: The Evaluation of Small Fiber Neuropathy
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Systematic Review Presents Current Understanding of Small Fiber Neuropathy
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The review, published in the May 2016 issue of Muscle & Nerve, provides a comprehensive evaluation of Small Fiber Neuropathy (SFN) research. [Read More]
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Epidermal Nerve Fiber Density Test – Biopsy Sites
Standard Biopsy sites for ENFD Testing
Therapath has established five standard biopsy sites for Epidermal Nerve Fiber Density (ENFD) and Sweat Gland Nerve Fiber Density (SGNFD). These sites allow for the diagnosis of a Small Fiber Neuropathy affecting either the upper or lower extremities in patients 18 and older.
The standard sites include the Proximal Arm, Distal Arm, Thigh, Distal Leg, and Foot. More details are available on our biopsy procedure guide.
The Epidermal Nerve Fiber Density (ENFD) test measures the density of the small sensory nerve fibers in the skin, and the Sweat Gland Nerve Fiber Density (SGNFD) test measures the density of the small autonomic nerve fibers in the sweat glands.1,2 The same biopsy sample can be used for both tests.
The skin biopsy procedure can be performed at the physician’s office and is reimbursed using CPT codes 11100 and 11101.

- Joint T. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society. J Peripher Nerv Syst. 2010;15(2):79-92. [PubMed]
- Gibbons C, Illigens B, Wang N, Freeman R. Quantification of sweat gland innervation: a clinical-pathologic correlation. Neurology. 2009;72(17):1479-1486. [PubMed]
Related Articles
Abstract: The Evaluation of Small Fiber Neuropathy
Becky Tsai2022-09-05T17:46:29-05:00
Thawani el al. recently conducted a survey of neurologists regarding their evaluation of patients with small fiber neuropathy. [Read More]
Systematic Review Presents Current Understanding of Small Fiber Neuropathy
Becky Tsai2022-09-05T17:47:23-05:00
The review, published in the May 2016 issue of Muscle & Nerve, provides a comprehensive evaluation of Small Fiber Neuropathy (SFN) research. [Read More]
New Study Examines Fixative Solutions Used in Skin Biopsy Test for Small Fiber Neuropathy
Becky Tsai2022-09-05T17:48:19-05:00
Therapath LLC finalized a comparison study of the most common fixation methods used in Epidermal Nerve Fiber Density testing for the determination of SFN. [Read More]
Therapath Neuropathology Announces National Ophthalmic Pathology Program
Becky Tsai2022-09-05T17:49:10-05:00
Therapath LLC, a leader in neuropathology laboratory services, launches its national ophthalmic pathology program. [Read More]