The goal of this two-center, randomized, double-blinded, parallel-group, placebo-controlled clinical study is designed to compare the efficacy of twice daily applications of ATX01 versus placebo during two consecutive 3-week treatment periods. The primary objective is the comparison between Treatments (ATX01 15% vs. Placebo) of mean pain attack intensity score assessed for the final week of each treatment period using an 11-point Numerical Pain Rating Scale (NPRS). Mean pain attack intensity is defined as the sum of the pain intensity score of each pain attack during the last 7 full days (Day 14 to Day 20) of each Treatment Period divided by the total number of erythromelalgia pain attacks during that 7-day period.
Participants will apply on feet and/or hands twice a day in the morning and in the evening, approximately 12 hours apart from the morning administration for 3 consecutive weeks each and record the pain intensity of each attack that occurs.