There are three major types of EB and each is a distinct condition:
- simplex (EBS) - Weber Cockayne EBS, Köbner EBS and Dowling Meara EBS
- dystrophic (DEB) - recessive dystrophic EB (RDEB) and dominant dystrophic EB (DDEB)
Within each group there are different sub-types which vary in their severity and associated clinical features. In the milder forms children may have blistering limited to the feet and hands, but in the more severe forms, EB may be very disabling, painful and life-threatening.
If a child has one type of EB, they cannot later develop one of the other forms of EB.
What causes epidermolysis bullosa?
The problem lies in the genes that hold the instructions necessary for production of certain proteins in the top layer of skin.
These instructions have a minor fault, rather like a typing error, with the result that the proteins are incorrectly formed, and unable to fulfil their role as scaffolding for the topmost layer of skin. The result is that the layers of skin do not ‘stick’ securely to each other, and where the layers separate a blister develops.
EBS is usually a dominantly inherited condition seen equally in males and females. This means anyone who has EBS can pass the condition onto their children. Each time a pregnancy occurs, there is a one in two chance that the child will inherit EBS if one parent is affected. EBS can sometimes be seen as a ‘new mutation’ when there is no family history.
Dystrophic EB (DEB) is found equally in males and females. There are two types of inheritance in dystrophic EB. These are called dominant and recessive.
In dominant dystrophic EB (DDEB) a defect in one of the genes inherited can lead to fragile skin and blistering, even though the other gene is normal. This means anyone who has DDEB can pass the condition onto his or her children.
Each time a pregnancy occurs, there is a one in two chance that the child will inherit DDEB, if one parent is affected. However, DDEB can sometimes be seen as a ‘new mutation’ when there is no family history.
In recessive dystrophic EB (RDEB) both copies of the gene have to be defective in order for the person to have fragile skin and blisters. A person with one defective copy of the gene is healthy and is said to be a carrier of the disorder. However, if two such people who carry a defective copy have children, there is a one in four risk that the child will inherit both defective copies of the skin and will have fragile skin and blisters.
RDEB varies tremendously in severity as the gene responsible for the condition is very large, and the defect can occur on any part of the gene.
What are the signs and symptoms of epidermolysis bullosa?
A child will have a tendency for the skin to blister after minimal friction or trauma.
Weber Cockayne EBS is the most common type of EBS. Blistering is localised to the hands and feet. Blisters may not become evident until the child begins to walk.
In Köbner EBS, blistering may be obvious from birth, or develop during the first few weeks of life. Sites of blistering respond to areas where friction is caused by clothing and frequently appear around the edges of the nappy. Blisters are often seen inside the mouth but do not generally cause a problem during feeding.
How is epidermolysis bullosa treated?
There is currently no cure, but research continues. There is still along way to go, but an effective treatment to prevent the skin problems may ultimately be possible.
There are some ways to help ease the symptoms of certain types of EB.
Management involves identifying new blisters, lancing them with a sterile needle, or snipping with a sharp pair of scissors to release the fluid and prevent spread. If compressing the blister to expel the fluid is very painful, then the fluid can be drawn off using a fine needle attached to a syringe.
Many people find dressings unnecessary, preferring to dust the area with corn flour to help dry up the blisters and reduce friction. However, some non-stick dressings that could be tried are Aquacel (Convatec) and Mepitel or Mepilex transfer/lite (Mölnlyke) dressings with a cooling effect such as Actiform Cool (Activa) and Intra Site Conformable (Smith and Nephew) which can help in reducing pain. These dressings can be held in place with a sock, cotton bandage or tubular bandage such as Tubifast. Dressings are continually evolving. The EB team can advise on up to date appropriate dressings.
Blisters can be very painful and limit mobility. Some people find it helpful to take simple painkillers such as paracetamol and ibuprofen when their feet are especially sore.
Longer-term pain management may be necessary, sometimes only in the summer months when blistering is at its most troublesome.
Occasionally, a person can get a blister around the anal region (bottom), which can then make it painful when passing faeces (poo). This in turn leads to constipation, as a child is frightened to poo because it hurts.
If this occurs, it is important not let this continue. A good diet with plenty of fluids helps. Occasionally medicines to help soften the faeces or to stimulate the bowel are prescribed.
DDEB and mild RDEB
Blisters should be lanced with a sterile needle in order to prevent them from enlarging. The roof should be left on the blister and the area dusted with corn flour to help it to dry up. Where a knock or fall has removed the skin leaving an open wound, a dressing needs to be applied.
It is recommended Mepitel (produced by Molnlycke) directly to the skin, this should then be covered with Mepilex (Molnlycke) where padding is required for protection, or Mepilex Transfer (Molnlycke) on areas which require a thinner, more conformable dressing. These dressings are secured with a tubular bandage such as Tubifast. Wounds on knees and elbows can be dressed with Mepilex Border, which is self-fixating and does not require a tubular bandage to keep it secure.
All the described dressings are designed to be left in place for several days to allow healing to take place. Mepilex, Mepilex Transfer and Mepilex Border can also be used to pad vulnerable areas such as ankles, knees and elbows.
In those with DEB, the wounds and blisters tend to heal with a scar. Often little white raised spots are seen in the scar tissue. These are called milia and they eventually disappear and do not cause any problems. The scar tissue is fragile and for this reason we suggest padding vulnerable areas of skin as described above.
The mouth and throat
Blisters are often seen in the mouth in those with mild DEB, but rarely cause problems with eating and drinking. There is a small risk that blisters in the oesophagus (food pipe) can develop and these may heal with a scar, which causes a narrowing or stricture.
In order to prevent this, a doctor may prescribe medicines to neutralise the acid in the stomach. This means if stomach contents are refluxed up the oesophagus, which is very common in babies and young children, the skin lining the food pipe is protected from the acid.
This is a very common problem in all types of EB, even those with mild DEB. Blisters around the anal region (bottom) can make it painful to pass faeces. Constipation then develops because the child is frightened to poo in case it hurts.
A good diet, high in fibre with plenty of fluids will help. Sometimes medicines are prescribed to help soften the faeces or stimulate the bowel.
What will help?
There are no measures that will totally stop all blisters forming, however the following actions can be carried out to minimise the risk.
Heat, especially when associated with high humidity can exacerbate blister formation, so measures taken to keep affected areas cool will often reduce the rate of blistering.
- wear natural materials
- soak area (eg hands and feet) in cool water, especially after a hot day
- temperature regulation in house/classrooms
Choice of footwear
Choice of footwear is very important.
- Natural materials for shoes are good, such as leather.
- Check the insides of new shoes for excessive seams, as these could cause blisters.
- Children should get their feet measured to ensure good shoe fit.
A recommended make is Ricosta, available from good shoe shops. Some people find the use of insoles or special socks beneficial, for instance, Carnation make socks containing a silver thread which helps to keep the feet cool. “Silversocks” are available from Carnation Footcare, Cuxson Gerrard & Co Ltd, Freepost BM4571, 125 Broadwell Road, Oldbury, West Midlands B69 4BR. Cushioning insoles are available from the same company.
Walking some days will not be a problem but some days can be difficult. Many people ‘save’ themselves to do activities that they enjoy.
What happens next?
DEBRA is a charity set up to help people with EB. They provide information, practical help, and professional help from nurses, social workers, welfare workers and a means of communicating to families via newsletters and conferences.