Small fiber neuropathy is a type of peripheral neuropathy. Peripheralneuropathies affect the peripheral nervous system. This includes the nerves outside of the brain and spinal cord. With small fiber neuropathy, the narrow nerve fibers of the peripheral nervous system are affected.

How is it diagnosed?

Doctors use a variety of different evaluations to diagnose this condition.

Your doctor will ask you about your symptoms, medical history, and family history. This can help them identify diagnosed or undiagnosed conditions that might be contributing to your symptoms.

Your doctor might recommend a nerve conduction test along with an electromyography. These two tests can be used to rule out large fiber peripheral neuropathies, which can cause similar symptoms. When the results of these tests are normal, other tests are needed to assess small fiber damage.

Skin biopsies are the most effective way to diagnose small fiber neuropathy. They’re only mildly invasive. During the procedure, the physician will remove several tiny skin samples, typically from the legs. The samples are then examined under a microscope for signs of small fiber neuropathy.

Quantitative sudomotor axon reflex testing (QSART) tests autonomic function. It measures the amount of sweat produced when the skin is stimulated with a mild electrical shock. People who have small fiber neuropathy are more likely to have low sweat output.

Your doctor might use other tests to identify or rule out medical conditions related to your symptoms. Blood tests, genetic testing, and imaging tests are other common diagnostic tests.

How is it treated?

Treatment depends on the underlying condition. For example, small fiber neuropathy caused by prediabetes or diabetes is treated by managing blood sugar levels and maintaining a healthy weight. When the cause hasn’t been identified, treatment focuses on managing symptoms. Pain-related symptoms are typically treated with medication.