Peripheral nerves serve several functions in the body that include locomotion, balance, and monitoring and protection from external environment. The protective functions in the nerves are served by small nerve fibers that detect pain and temperature sensations. These small nerve fibers connect with the skin including the outer layer of the skin called epidermis. In some sensory neuropathies these fibers are selectively affected. Over the last several years techniques have been developed that now allow to assess integrity and health of small nerve fibers in the skin. Skin biopsies allow diagnosis of sensory neuropathy and could lead to the detection of underlying disorders that cause injury to small sensory nerve fibers.
Stages of the Procedure
Before the Procedure
- Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure. You will be asked to sign a consent form that provides permission to perform the procedure. Read the consent form carefully and ask questions if something is not clear.
- Notify your physician if you are sensitive to or are allergic to any medications, latex, tape, and anesthetic agents (local and general).
- Notify your physician of all medications, especially about blood thinners such as aspirin or Coumadin.
During the Procedure
Skin biopsies are done on an outpatient basis, and the procedure is typically completed within 15–30 minutes. Biopsies are typically performed in the leg for the diagnosis of sensory neuropathy. Skin is cleaned and injected with local anesthetic. 3 mm punch biopsies are performed in the anesthetized area. Band-Aid is applied to the biopsy site. The skin heals within 2–3 weeks, minimal scarring may occur at the biopsy site. Other risks, which are very rare, include bleeding and infection.
After the Procedure
Keep the biopsy site clean and dry at all times. Change the Band-Aid daily. Do not apply aloe vera, ointment, or any topical antibiotics over the biopsy site. You can take a shower by wrapping saran wrap around the biopsied site. If for any reason the site becomes wet, you can dry it and put a new Band-Aid. When the scab is formed and new skin is growing, then the bandage can be removed. You can take over the counter pain medications (Tylenol) if you experience pain at the biopsy site. If you experience excessive bleeding, oozing, redness, or warmth at the site, please contact your doctor’s office as this might be a sign of an infection.