Epidermolysis bullosa (EB) Q & A
What is EB?
Epidermolysis bullosa (EB) is a distressing and painful genetic skin condition causing the skin layers and internal body linings to separate and blister at the slightest touch.
How is EB caused?
EB is a genetic condition and is inherited.
Is EB contagious?
No, EB is not contagious. As it is a genetic condition it cannot be ‘caught' by being in contact with someone who has EB.
How common is EB?
EB is a rare condition. An estimated 1 in 18,000 babies born are affected by EB.
How is EB inherited?
EB is passed from parent to child, as with most other physical traits. It is described as being either dominant, recessive or sporadic. In recessive cases both parents pass a faulty copy of a gene to the child but neither parent has the condition. In dominant forms a faulty copy of a gene is inherited from one of the parents, who generally also has EB. Sporadic (or random) cases are also common in EB, where the faulty gene is not passed from the parents but is due to a ‘new' change in the child's DNA.
It should be pointed out that having faulty genes is not uncommon. In fact we all have a certain number of faulty genes but in most cases they do us no harm and we are not aware of them.
What genes cause EB?
There are a number of genes associated with the skin that can cause EB if they have a fault in them. They are called such names as collagens, keratins and intergrins. In all cases however, they are responsible for making proteins which are important for the structure of the skin.
How do faulty genes result in the symptoms of EB?
Genes are responsible for making proteins which can be considered the ‘work horses' of the body. All the genes involved in EB are responsible for making proteins which are important for the structure of the skin. The skin is made of different layers and these proteins bind the layers together. When they are reduced, absent or functioning incorrectly, the layers of the skin can separate, resulting in blistering and wounding.
Are there different types of EB?
Yes, there are different forms of EB that range from being mild to severe. As mentioned, there are many different genes responsible for EB and these give rise to different forms of EB. Broadly however, there are three major subtypes: EB simplex, junctional EB and dystrophic EB (more information).
Can one form of EB become another?
No, one form of EB cannot become a different form. For instance, if you have been diagnosed with a mild form of EB you will never develop one of the more severe forms. Many of the symptoms are specific to only one form of EB and will not be experienced by people living with another form.
How is EB diagnosed?
If EB is suspected by medical staff because of physical symptoms, then a small sample of skin will be taken for examination under a microscope. This gives a very good indication of whether the symptoms are caused by EB and if so, what form of EB it is. Where possible the diagnosis is confirmed by genetic testing.
Is it only the skin that is affected in EB?
In very mild cases, yes, it is only the skin which is affected. In more severe cases however, the internal linings of the body (such as the mouth, oesophagus and intestines) can be badly affected as well. Other tissues which may be affected include the teeth, nails and eyes. In some severe forms the fingers and toes can fuse to give a mitten-like appearance. Although there are characteristic symptoms of EB they vary hugely between patients. While we tend to talk mostly about the effects on skin, many of the potential treatments currently being researched will treat both external and internal wounding.
Is there a cure for EB?
No, there is currently no cure for EB. Treatment of the condition presently consists of the management of symptoms, which has improved dramatically over the years. There is much research being undertaken world wide however, to find effective treatments and cures. DEBRA Ireland is funding a variety of projects aimed at developing treatments and cures for EB (please see our research pages for more detail).