Acral pain and paresthesia related to small fiber neuropathy: Changes in thermoregulatory sweat test

초록

Objective: Acral pain is a frequently encountered somatic pain disorder, which can be difficult to diagnose. Small fiber neuropathies have been known to cause acral pain, paresthesia, dysesthesia and also sweating disorder, orthostatic intolerance. We have developed thermoregulatory sweat test (TST) machine and applied it to diagnose small fiber neuropathy. Cases: 3 Patients with pain or sensory disturbances in feet (2 diabetic, 1 unknown) have been studied. Family, occupational histories were taken. Laboratory tests for soft tissue inflammatory disorders (ESR, CRP, Rheumatoid factors, anti-CCP, anti-nuclear antibodies), nutritional study (vitamin B12, Folic acid), liver function, anemia, metabolic disorders (glucose, HbA1c, thyroid function test) were evaluated. Spinal imaging including MRI or CT studies were done. Motor and sensory nerve conduction studies (NCS), sympathetic skin responses and TST were done. Results: Laboratory tests, radiologic evaluations, NCS, and SSR were found unrevealing. TST showed reduced sweat patterns in feet area. And these cases were diagnosed as small fiber neuropathies. Conclusion: We expect TST could be applied for the diagnosis on acral painful disorder related to small fiber neuropathy.