Small fiber neuropathy is increasingly being recognized as a major cause of painful burning sensations in the feet, especially in the elderly. Although strength remains preserved throughout the course of the disease, the pain and paresthesias are often disabling. Diabetes mellitus is the most common identifiable cause of small fiber neuropathy, and impaired oral glucose tolerance and individual components of the metabolic syndrome are often associated with it. Some cases, however, are idiopathic. Skin biopsy (with an evaluation of the density of intraepidermal nerve fibers) and tests of autonomic nerve function are useful for the diagnosis. Management involves controlling pain and identifying and aggressively treating the underlying cause.
Small fiber neuropathy: A burning problem. Cleve Clin J Med. 2009 May