The intravenous infusion of mesenchymal stem cells from family donors is safe and improves symptoms such as pruritus (itching), sleep disturbances, and fatigue associated with Recessive Dystrophic Epidermolysis Bullosa (RDEB), popularly known as "butterfly skin." This is one of the primary conclusions of a clinical trial conducted by researchers from the Universidad Carlos III de Madrid (UC3M), the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) of the Ministry of Science, Innovation and Universities, the Fundación Jiménez Díaz Health Research Institute (IIS-FJD), the CIBER Rare Diseases (CIBERER), and the La Paz University Hospital in Madrid.