Vascular and Neurologic Exploration of Small Nervous Fiber by Sudoscanner and QST

Erythromelalgy (EM) is a vascular syndrome very rare affecting the feet. This disease evolve by crisis when the feet extremities become red hot and painful. There are several types of EM but this study concern the adult primitive form. For a long time, the physiopathology was not described but now we know that there is a vascular form, with microcirculatory dysfunction and a neurologic form with small fibers neuropathy. The diagnostic of neurologic form is based on clinical evaluation (DN4 questionnaire, UENS scale...) and an electromyography. Thermotest, a medical device which measure the thermic sensitivity is used to quantify neuropathy. More recently Sudoscan, a device measuring cutaneous impedance to chloride ions detect small nervous fiber in diabetic patients with good correlation with Thermotest. The purpose of this study is to analyze the vascular side and the neurologic side on patients consulting for Erythromelalgy.

patient will be measured chlorine ions impedance with the SUDOSCAN and evaluation on pain du to temperature with the THERMOTEST

Measurement of chlorine ions impedance by SUDOSCAN and pain due to temperature evaluation with THERMOTEST

Inclusion Criteria: Pain with burn feeling at hands and feet extremities Crisis activated by the heat Age > 18 years old Exclusion Criteria: Patients who had burn in extremities