If your doctor ordered a cutaneous nerve biopsy, he or she might suspects that you have a neuropathy— a problem with these sensory nerves, which enable the feelings of touch, heat and cold, and pain. A neuropathy can cause sensations of tingling, numbness, burning or pins and needles.

A cutaneous nerve biopsy is a simple minimally invasive test that helps your doctor examine the sensory nerves. A medical professional can perform the test right in the doctor’s office or in a clinic following these steps:

• The doctor, nurse or staff member numbs an area of your arm or leg and removes a very small sample of skin.
• This sample is shipped to the Johns Hopkins Cutaneous Nerve Laboratory, where it is treated with special stains that make the nerves within the skin easier to see under the microscope.
• Cutaneous Nerve Laboratory informs your doctor of the findings from the test, and the doctor then can discuss them with you. Turnaround time is typically under 3 weeks.

Request an Appointment

You can get a cutaneous nerve biopsy at the Johns Hopkins Outpatient Center or in the neurology clinic at Johns Hopkins Bayview Medical Center. Biopsies are performed by trained staff.

To request an appointment for a cutaneous nerve/skin biopsy, please have your doctor contact our office at 410-502-7930. You can also call this number with any questions or concerns.

Please be aware that the specialists working in our lab are not permitted to provide medical advice.

How We Analyze the Sample

The sample is processed to allow for us to identify, visualize and count small sensory nerve fibers in the skin, as well as assess their state of health. In general, when these nerves are affected by a peripheral neuropathy, the number and shape of the nerves is abnormal and can be recognized under the microscope.

Although the test cannot determine the exact cause of your symptoms, cutaneous nerve biopsy can provide information about your sensory nerves that helps your doctor determine what tests and treatments may be best for you.

Patient Instructions for Biopsy Site Care

1. Leave your wound dressings in place for the rest of the day of the biopsy and keep them dry.
2. Refrain from doing extremely strenuous activity for the rest of the day of your biopsy (such as running or heavy lifting).
3. Change band-aids daily starting the day after the biopsy until there are no open wounds. This can take anywhere from 1 or 2 days up to 2 weeks (5-6 days is average for daily band-aid changes). 
4. The wounds may or may not form a scab as they heal; either is fine.
5. Showers are fine starting the day after the biopsy. Leave the band-aids in place while you shower and change them after you dry off.
6. During the time period of daily band-aid changes, do not soak in a bath or swim.
7. If you need to clean the wounds, you can use hydrogen peroxide. If the wounds are fine (no signs of infection), a daily band-aid change is all you need.
8. The local anesthetic used for the biopsy will usually last for 1 to 2 hours after the procedure. After it wears off, you may have some mild localized soreness and tenderness at the biopsy sites over the next day or two. You may find regular Tylenol is helpful for the discomfort.
9. Once the biopsy sites heal, they may look slightly red or darker than the rest of the skin. This discoloration will gradually fade and blend with your normal skin color. This fading process may take anywhere from a few months up to a year.
10. Problems during the healing period are very rare. It is normal for the biopsy sites to bleed a little or drain pink fluid for a day or two after the procedure. They should not bleed excessively (i.e., through the band-aid) after that time. They should never drain pus. If you experience problems with significant bleeding, redness, infection or other problems, call your doctor's office.