An Epidermal Nerve Fiber Density (ENFD) test is a lab service to identify small nerve fibers density.

Epidermal Nerve Fiber Density (ENFD)

The test is 95%-to-97% in specificity and the sensitivity is approximately 90%. The Epidermal Nerve Fiber Density (ENFD) test is the best objective tool for documenting small fiber peripheral neuropathy by quantifying the terminal branches of peripheral nerves within the epidermis. ENFD analysis allows for the direct visualization of small nerve fibers. Small nerve fibers are assessed for structural integrity and counted. A diminished number of small nerve fibers are indicative of established diseases; the lower the count, the more severe the disease state. ENFD testing measures degeneration, but can also be used as a predictive tool, and to assess the effectiveness of therapy over time. 

Conditions associated with small fiber peripheral neuropathy:

• Metabolic (diabetes mellitus, metabolic syndrome, hyperlipidemia)

• Inherited (Fabry’s disease, Tangier’s disease, familial amyloid polyneuropathy)

• Toxic (chemotherapy, alcoholism, solvent exposure)

• Autoimmune (Sjögren’s syndrome, vasculitis/polyarteritis nodosa)

• Amyloidosis (non-inherited forms of amyloidosis, e.g. lymphoma or plasma cell dyscrasias)

• Infectious (HIV, hepatitis C, Lyme disease)

• Idiopathic (For a relatively large percentage of cases, there is no identifiable cause of SFPN