The cutaneous nerve biopsy: technical aspects, indications, and contribution.

Area of Science:

• Neurology
• Dermatology
• Pathology

Background:

• Skin biopsy allows visualization of epidermal, dermal, and sweat gland nerve fibers.
• The "blister" technique samples the epidermis using suction.
• Immunohistochemistry with protein gene product 9.5 (PGP 9.5) is commonly used.

Purpose of the Study:

• To highlight the diagnostic value of skin biopsy in small fiber neuropathy.
• To discuss the application of skin biopsy in monitoring nerve fiber degeneration and regeneration.
• To explore the utility of skin biopsy in diagnosing various neuropathies.

Main Methods:

• Skin biopsy using a 3mm punch or suction capsule.
• Immunohistochemical staining for PGP 9.5.
• Analysis via bright-field or immunofluorescence microscopy, including confocal microscopy.

Main Results:

• Intraepidermal nerve fiber density quantification is a common reporting method.
• Normative values for nerve fiber density have been established.
• Skin biopsy can reveal nerve fiber degeneration in diabetes and other neuropathies.

Conclusions:

• Skin biopsy is crucial for diagnosing small fiber neuropathy when nerve conduction studies are normal.
• The technique allows for monitoring disease progression and treatment effects on nerve regeneration.
• Skin biopsy can identify specific nerve fiber abnormalities in diverse neuropathic conditions.