Skin biopsy

During a skin biopsy, a small circle of skin tissue is removed using a tool called a punch (like a cookie cutter). The procedure is done on an outpatient basis using a local anesthetic.

Why would a skin biopsy be recommended for a neurological issue?

Your HonorHealth neurologist might recommend a skin biopsy to check for small fiber sensory neuropathy. Your nerves are made up of fibers of different sizes. Small fibers sense pain and temperature sensations while large fibers assist with balance.

Small fiber sensory neuropathy is typically characterized by numbness, tingling and pain involving any part of the body but most often the feet. The pain is usually described as a burning, electric-like or stabbing sensation. However, sometimes it might cause only muscle pain.

Small fibers travel slowly, and their response to stimuli can’t be picked up by an EMG, which would typically be used to evaluate large sensory and motor nerve fibers. The best way to test the small fibers is by a skin biopsy.

How should you prepare for a skin biopsy?

Biopsies don’t require much preparation. You’ll likely have a physical examination during which you’ll give your medical history including a list of any prescription medications, over-the-counter medicines and/or supplements. Your doctor may have you stop taking certain pain relievers, supplements or blood thinners for a short period prior to your procedure.

You should refrain from eating and drinking eight hours before your biopsy. You should arrange for someone to drive you home.

What can you expect during a skin biopsy?

Biopsies are relatively simple procedures. You’ll go home the same day and will quickly resume your routine activities.

Skin biopsies usually are taken from the skin surface at one or more of three sites: above the ankle, above the knee and below the hip. The biopsy size is small — about the size of a pencil eraser — so you won’t need stiches. A bandage will cover the sites, which will heal by scabbing over. The sites should heal within a week, although you may notice small scars.

The procedure takes about 10 to 15 minutes. You shouldn’t have any pain, although you might feel a burning sensation for a few seconds when the anesthetic is injected to numb the sites.

What should you expect after a skin biopsy?

You can continue activity as usual after your biopsy. You can take a shower. However, to prevent infection you’ll need to avoid baths or swimming for a week after the procedure.

The specimen is processed in a way that allows your skin’s small nerve fibers to be visualized and counted. Small fiber sensory neuropathy may be diagnosed if the small nerve fibers are less dense than normal.

Your physician will have the results in about two weeks.

Find a neurologist in the Phoenix area or call 623-580-5800 for a referral.