Understanding SFN
Small fiber neuropathy (SFN) is a type of peripheral neuropathy, affecting only the small sensory skin nerves. The frequency of SFN is not known. Diabetes mellitus and impaired glucose tolerance (how the body breaks down sugars) are the most common diseases that lead to SFN. Other causes include Fabry disease, immune disorders such as celiac disease or Sjogren syndrome, sarcoidosis, and human immunodeficiency virus (HIV) infection. It can be caused by a mutation in certain genes.
Symptoms of SFN
SFN symptoms can cause intense, mainly sensory pain episodes and include unusual sensations such as pins-and-needles, pricks, tingling and numbness. Some patients may experience burning pain or coldness and electric shock-like brief painful sensations. Some patients have an increased sensitivity to pain in general and experience pain from stimulation that typically does not cause pain. Individuals affected by this condition may also have a reduced ability to differentiate between hot and cold while in others, the pain attacks are caused by cold or warm triggers. In most patients, symptoms start in the feet and move upwards. In advanced cases, it may involve the hands.
Some individuals have urinary or bowel problems, episodes of rapid heartbeat (palpitations), dry eyes or mouth, or abnormal sweating. They can also experience a sharp drop in blood pressure upon standing (orthostatic hypotension), which can cause dizziness, blurred vision, or fainting.
Diagnosing SFN
Diagnosis is based on history, clinical examination and supporting laboratory testing. Electromyography (EMG) and nerve conduction studies (NCS) are done to rule out other conditions. Skin biopsies are used to confirm the loss of nerves to the skin.
Treatment of SFN
There is no cure for small fiber neuropathy (SFN). Treatment includes managing symptoms as well as the underlying cause. If SFN is caused by diabetes, then the treatment is aimed at correcting the diabetes (for example, through diet, exercise, and/or diabetes medication). SFN may be caused by an autoimmune problem, which is when the immune system malfunctions and creates antibodies that attack and cause damage to a part of the body (in this case, the nerve fibers). If this is suspected, a treatment option is immune globulin therapy administered into the blood stream intravenously (IVIG).
References:
- Small Fiber Neuropathy | Medline Plus
- Small Fiber Sensory Neuropathy | Johns Hopkins Medicine
- Liu X, Treister R, Lang M, Oaklander AL. IVIg for apparently autoimmune small-fiber polyneuropathy: first analysis of efficacy and safety. Ther Adv Neurol Disord. 2018;11:1756285617744484. Published 2018 Jan 8. doi:10.1177/1756285617744484
Last reviewed 12/16/2025
