Evaluation of the Efficacy of ROPIVACAINE in Children and Young Adults With Hereditary Epidermolysis Bullosa

This clinical trial aims to determine the efficacy on pain of local application of ROPIVACAINE 0.2% on cutaneous lesions related to Epidermolysis Bullosa during dressing change, associated with the standard premedication. Patients will be hospitalized and will have several baths. The first bath will be done according to usual protocol (usual premedication 1h before the bath). Pain measurements (Visual analog scale or FLACC) will be done at the entry into the water, in the middle of bath and at the time of the dressing change. The following baths will be done using local application of Ropivacaine 15 minutes before entering into the water on lesions identified by the patients as the most painful lesions due to Epidermolysis Bullosa. A blood test will be done during the first use of Ropivacaine to determine plasmatic level of Ropivacaine. After 3 baths in the dermatology unit, patients will continue such bath at home, every 48h during 15 days.