Normative Data of Intra-epidermal Nerve Fiber Density

Inclusion Criteria: * Man or woman between 20-80 years old * Normal subjects without pain and neurological impairment * No history of neurological disorder * Normal neurological examination * Normal ECG * Normal clotting sample from less than 6 months * Available by phone Exclusion criteria : * History of alcoholic intoxication or chemotherapy * History of diabetes, kidney insufficiency, monoclonal gammapathy, B/C hepatitis, HIV, coeliac disease, sicca syndrome, raynaud syndrome, systemic erythematous lupus, Fabry disease, amylosis, vascularitis * Contraindication to xylocaïn with adrenalin * At the site of biopsy : surgery, skin pathology, infection, vascular insufficiency * Innate or acquired immunosuppression * Innate or acquired clotting abnormality