What is recessive dystrophic epidermolysis bullosa (RDEB)?
Epidermolysis bullosa (EB) is a group of rare genetic skin diseases of which Dystrophic EB (DEB) is one of the most severe forms. There are two main types of DEB – the dominant form (DDEB) when the affected person inherits the altered gene from only one parent and the recessive form (RDEB) when the affected person inherits one copy of the altered gene from each parent. RDEB tends to be generally more severe than DDEB.
People with DEB have blistering of skin and mucosal membranes that line many tracts and structures of the body, such as the mouth, food pipe etc. Children with DEB are often called ‘Butterfly children’ as their skin is as fragile as the wings of a butterfly. This fragility results from a very weak connection between the dermis (inner layer) and the epidermis (outer layer) of the skin. People with DEB live with constant pain and have a high risk of malnutrition and infections. Symptoms include poorly healing wounds, skin infections, fusion of fingers and toes (pseudosyndactyly), anemia, gastrointestinal tract problems and with adulthood some develop very aggressive forms of squamous cell carcinoma (skin cancer).
What causes DEB?
DEB is caused by mutation(s) (or mistakes) in a gene in the DNA called the COL7A1 gene. This gene is responsible for the formation of collagen type VII (C7) protein that forms anchoring fibrils that bind the dermal (inner) and epidermal (outer) skin layers together. The mutations can occur in different parts of the COL7A1 gene and cause loss or malfunction of the anchoring fibrils. This leads to the fragile skin in DEB patients.
Currently, there are no approved treatments available that target the underlying cause of DEB. Patients receive treatments that focus on disease management, prevention of complications and prevention of the formation of new blisters. There are palliative treatment options focused on wound care (bandaging, prevention of infection, better wound healing), pain management and itch management. Other points of attention are bone care, nutrition (due to eating difficulties), oral care and eye care. In addition there is a close surveillance for skin cancer, to which some DEB patients are especially vulnerable.