Treatment of Erosive Digital Osteoarthritis by Transcutaneous Auricular Nerve Stimulation

Inclusion Criteria: * Age≥18 years * Symptomatic HOA (1990 American College of Rheumatology criteria) * EHOA according to hand radiographs with ≥1 erosive digital joints of proximal or distal interphalangeal joint (phases "E" or "R" of Verbruggen-Veys score) * Visual Analogic Scale (VAS) for hand pain ≥ 40/100 at inclusion -≥1 interphalangeal joints symptomatic ≥ 3 months despite analgesics or non-steroidal anti-inflammatory drugs (NSAIDs) (or contraindicated) * ≥1 symptomatic interphalangeal joint with clinical palpable synovitis at inclusion * Informed written consent Exclusion Criteria: * Isolated thumb-base OA (ie, rhizarthrosis) * Hand osteoarthritis secondary to other known causes (eg gout, psoriatic arthritis) * Psoriasis * Current skin disease of the ear * Ear canal not adapted to apply the auricular electrode * History of severe cardiac disease (coronary artery disease, rhythm disturbance, heart failure, valvulopathy) * Conduction or rhythm disturbances on electrocardiogram * Symptomatic orthostatic hypotension or vasovagal syncope history * History of vagotomy * Pregnancy * Fibromyalgia * Use of other electrically active medical devices (eg pacemaker) * Documented sleep apnea * Use of corticosteroid (oral, intramuscular, intra-articular or intravenous), immunosuppressive agents, hyaluronic acid injection in interphalangeal joint within the last 3 months * Hand surgery planned during the study period * Pregnancy or breastfeeding if applicable * Oral NSAIDs consumption during the last 48 hours before inclusion