Epidermolysis Bullosa has been categorised as encompassing 5 major types (Simplex, Junctional, Dystrophic, Kindler Syndrome, Aquisita) and 31 subtypes, therefore it is commonly referred to as a group of disorders. Other manifestations of EB include: anemia, cardiomyopathy, syndactyly (fusion of the fingers and toes), renal insufficiency, dysphagia (difficulty in swallowing), malnourishment, cancer, constipation, osteoporosis, muscular dystrophy, and pyloric atresia.
In this type, blistering occurs in the upper layer of the skin called the epidermis. It is characterised by a lack of adhesion of the skin directly above the basement membrane (the basal layer). EBS is the most common type of EB, and is held accountable for 70 percent of cases. EBS is generally milder than other types of EB, although the blistering is painful and easily compounded by rubbing.
In this type, blistering occurs in a skin layer called the lamina lucida within the basement membrane zone, which is situated at the junction between the epidermis (upper layer of the skin) and the dermis (lower layer). JEB is the most severe type of EB and accounts for about 5 percent of cases.
In this type, blistering occurs in the lamina densa, which is a component of the basement membrane zone between the lamina lucida and the underlying dermis of the skin. DEB accounts for about 25 percent of cases. DEB is characterised by the scarring of the healed wounds, resulting in contraction of the joints, fusion of the fingers and toes, contraction of the mouth membranes, and narrowing of the oesophagus.
In this type of EB, blistering may occur at multiple levels within the basement membrane zone, or in skin layers beneath it.