What is Epidermolysis Bullosa?
Epidermolysis Bullosa is a rare inherited skin disorder that causes the skin to be so fragile that the slightest friction can cause severe blistering—inside and outside the body. Although a lot of research has been done over the past 20 years, there is still no cure. The condition varies widely in severity and forms. There are 3 known main types of EB, Epidermolysis Bullosa Simplex, Junctional EB and Dystrophic EB. However each of these can be categorised into different variations. So far, researchers have classified 27 variants of the condition, and there may be more that have not yet been identified. At its mildest, the blistering is confined to the hands and feet making holding things and walking extremely painful.
Other types of EB can be much more severe. Sufferers live in constant pain and scarring, which in the worst forms can lead to disfigurement, disability and often early death. Wound healing can be very slow, so having the right care is important. To avoid infections, dressings will have to be used to cover often large open wounds found all over the body. Strong medication including opioids such as Morphine and Midazolam are usually required on a daily basis to help ease the constant pain. Scarring limits the range of motion in limbs, making simple movements or even walking, unbearable. Fingers & toes can fuse together causing deformity & loss of function. Blistering and scarring internally often makes eating and drinking very difficult and painful. In EB’s worst forms, risk of developing a skin cancer in young age (squamous cell carcinoma) is very likely.
Click the links below for more information about the different types of EB:
Most of the EB sufferers are diagnosed with the mildest form called Epidermolysis Bullosa simplex. Although this type is non-disfiguring and non-lethal, it can be extremely difficult to live with. People with EB simplex develop blisters on their feet and usually also on their hands in response to friction. In EB Simplex the blistering occurs in the upper layer of the skin (the epidermis).
Junctional Epidermolysis Bullosa is considered the most severe form of EB. Of all EB sufferers approximately 5% have junctional EB. There are only a few patient with this severe type that survive the second or third year of life. The children often die during infancy due to infection, dehydration, malnutrition, anemia caused by serious blistering internally or externally. Junctional EB is inherited recessively, which means the parents carry the gene often unknowingly, and do not show physical signs of the conditions. The birth of a child with junctional EB is therefore, totally unexpected. The blistering occurs at the junction between the epidermis and the dermis (lower layer of the skin), in a layer of skin known as the basement membrane.
In Dystrophic Epidermolysis Bullosa the blistering occurs below the basement membrane zone in the upper part of the dermis. Sufferers have a weakened type of one of the most important proteins that holds are skin together, collagen 7. The dystrophic type may be inherited as a dominant or recessive trait. In the dominant type of EB one of the two genes that control the production of collagen 7, is faulty. These two collagen genes are inheritary, one from each parent. With this form of EB patient can lead an almost normal life. However, the severity of the disorder does increase at a later age due to scarring, fusion of fingers and wastage of skin tissue.
Less often dystrophic EB is inherited in a recessive fashion. The parents of a person with recessively-inherited Dystrophic EB usually have normal skin. Each unaffected parent has one normal and one abnormal type 7 collagen gene, and is able to make enough normal type 7 collagen to compensate for the weakening effect of the faulty gene. A child with recessive Dystrophic EB has two abnormal type 7 collagen genes, one inherited from each parent, and is unable to make any normal type 7 collagen. Each time the parents of a child who has recessively-inherited DEB have a further child, there is a 1 in 4 chance that the new baby will also have the condition. Only 25% of all EB sufferers have DEB and only small number of them have inherited it recessively. The risk of this occurring is very small indeed.
Click the links below to see pictures of EB (warning these images are quite graphic):