Small Fiber Polyneuropathy: An Update

Approximately 40 million people in the United States suffer from peripheral neuropathy and a growing subset of those appear to suffer from small fiber neuropathy. This presentation will review the causes and symptoms of small fiber neuropathy, a grossly underappreciated painful disorder that frequently is manifested by chronic widespread pain. Symptoms--burning and shooting pain, allodynia, and hyperesthesia--may result from myriad diseases, including diabetes, thyroid dysfunction, sarcoidosis, vitamin B12 deficiency, HIV, and neurotoxic medications, among others; however, often no specific cause is determined. Data about treatment specifically for small fiber neuropathy remain sparse. Recent guidelines propose using antidepressants, anticonvulsants, opioids, topical therapies, and nonpharmacologic treatments. History and physical examination are primarily used to diagnose this condition. Functional neurophysiologic testing and intraepidermal nerve fiber density evaluation using skin biopsy should also be used to confirm the diagnosis, as many patients are misdiagnosed as having fibromyalgia and continue to experience pain. For up to 50% of patients, the diagnosis may, however, remain "idiopathic." In this course, emphasis will be placed on determining the underlying etiology so that treatment can be tailored as much as possible, including management of associated neuropathic pain. (Recorded at PAINWeek 2016)