Painful Feet: The Small Fiber Neuropathies
Monday, April 28th, 2008Small fiber neuropathy is a relatively common disorder often associated with systemic conditions, such as diabetes, HIV, and vasculitis. Painful burning feet with diminished pain and temperature perception, and in some cases autonomic dysfunction, characterize this syndrome. Despite the magnitude of the symptoms there are few objective measures to identify and quantify these neuropathies. Skin biopsy and new immunohistochemical staining techniques have facilitated the evaluation of this syndrome.
Introduction. Peripheral neuropathies involve different populations of nerve fibers. Most patients present with large fiber neuropathies characterized by numbness, tingling, weakness, loss of deep tendon reflexes, and abnormal electrophysiologic studies. A more enigmatic group of patients present with severe pain and a paucity of findings on clinical examination and electrophysiologic studies. Many of these patients have small fiber neuropathies. The disparity of subjective sensory complaints to objective signs sometimes leads to an erroneous diagnosis of psychogenic pain. Patients with these syndromes are often difficult to treat. Thus, prompt evaluation and accurate identification of these syndromes is important.