When a patient experiences sensations including pins and needles, burning, stabbing, itching or prickliness, they may have small fiber neuropathy, a condition that is diagnosed through a skin punch biopsy.
Small nerve fibers connect pain receptors in the skin to the spinal cord and brain and can stimulate internal organs like the heart, gastrointestinal tract and bladder. These peripheral nerves can be unmyelinated or myelinated – a substance made of protein and fat – around their axons. Called the myelin sheath, this layer is necessary for the nervous system to function properly. When these small peripheral nerve fibers damaged, it is called small fiber neuropathy.
Symptoms of this neuromuscular disorder include:
- Severe pain attacks
- Numbness and tingling
- Widespread pain
- Hand and feet discoloration
- Abnormal sweating
- Blurry vision
- Heart palpitations and tachycardia
- Gastrointestinal symptoms
There are many causes of small fiber neuropathy. Common causes include diabetes, autoimmune diseases, toxicity and nutritional issues.
Small fiber neuropathy is diagnosed when a reduction in the epidermal nerve fiber density is found. Small sensory nerve fibers can be difficult to reveal with electromyography, so in order to establish an accurate diagnosis, we at Austin Neuromuscular Center (ANC) also perform skin biopsies to diagnose this condition.
Skin biopsies are minimally invasive and performed on-site under injected local anesthesia. Generally, a 2-millimeter-deep, 3-millimeter-wide piece of skin is removed with a small tool. The incisions are located above the knee and above the ankle. This procedure typically takes about 10 to 15 minutes, and complications are rare.
In addition to diagnosing small fiber neuropathy, other reasons we perform skin biopsies include:
- Confirming sensory neuropathy diagnosis in patients with symptoms of the condition and normal electro diagnostic study results
- Checking on progression of neuropathy to see if it is responding to treatment
- Diagnosing vasculitis neuropathy and amyloid neuropathy
- Finding causes of dysautonomia
- Providing documentation for insurance coverage
We may also recommend the procedure for patients with fibromyalgia and patients with unexplained muscle pain and cramps.
In order to improve turnaround time, improve pathology process quality and protect sample control integrity, we also offer in-house pathology services. Certified by College of American Pathologists (CAP) and Clinical Laboratory Improvement Amendments (CLIA). Dr. Yessar Hussain is certified to read and report on each sample processed in our lab.