Skinformation A - Z Skinformation Epidermolysis bullosa simplex What is epidermolysis bullosa simplex? Epidermolysis bullosa (EB) simplex is a rare inherited disorder in which the skin is fragile and blisters at sites of rubbing. It is mild in the usual form; blisters tend to be confined to the palms and soles, and are most troublesome during warm weather. In other types the blistering may be more generalised and occasionally blisters arise in the mouth. The most severe form is called EB simplex Dowling-Meara and those affected have more widespread blistering which does not vary according to the time of year. EB simplex is different from other types of EB which include junctional, dystrophic and Kindler forms; if you have EB simplex then you will not go on to develop these other types of EB. EB simplex is not an infection, it is not contagious and it is not due to an allergy. What causes epidermolysis bullosa simplex? The top layer of skin (the epidermis) is composed of layers of cells. Each cell has an internal support system formed from proteins (keratins), giving it strength and shape. In EB simplex, there is a weakness in one of these proteins (usually type 5 or type 14 keratin, but very occasionally another protein called plectin), which causes affected cells to be less resilient to friction and to rupture when subjected to even minor physical stress. When the cells break, they separate from each other, fluid accumulates between them and a blister forms. Weakness of the protein is caused by a minor abnormality (a mutation) in the gene responsible for producing that protein. A variety of such abnormalities have been identified in EB simplex, some of which are common amongst patients with the condition while other abnormalities are only found in individual families. Is epidermolysis bullosa simplex hereditary? Yes. It is inherited usually in a dominant fashion. This means that it needs only one affected parent to be transmitted to children, although it is possible to be a new abnormality that just appeared in the genes of that individual without the parents being affected. Anyone who has a dominant form of EB simplex can pass the condition on to his or her children: there is a 50% chance that the child of an affected parent will inherit the blistering tendency. EB simplex affects men and women equally. There is also a much rarer recessive form of EB simplex in which both parents are not affected but each carries an affected gene and they will have a one in four chance of having a baby with two affected gene who will then have the disease. What are the symptoms of epidermolysis bullosa simplex? The primary feature of EB simplex is blistering associated with friction. It is often painful and can sometimes significantly affect daily life and interfere with education and work. The age at which skin blisters develop depends on the sub type of EB simplex. Most commonly, the blisters occur for the first time during early childhood. Blisters may however start at birth or in adulthood. In early childhood, blisters tend to occur at site of friction such as under the elasticated areas of a nappy or the hands and knees during the crawling stage. Later, painful blisters tend to develop on the soles after walking only short distances. Writing with pens and pencils can cause blisters to appear on fingers, especially in children. Blisters may also appear under close fitting clothing such as waistbands, collars or the ribbing of socks. A few people find that hot food or hot drinks will cause blistering within the mouth. The formation of blisters is generally worse during warm weather. A few individuals may be free of blisters during the winter. Secondary infection of the blisters can be a common problem. Although blistering tends to be life long, it sometimes becomes less severe in adult life. In the Dowling-Meara variant of EB simplex, blisters occur for the first time at an earlier age, usually within a few days of birth. They can occur anywhere on the body and may be very extensive. The infant may be very unwell in the first few months of life but generally become much better after this. Dowling-Meara EB simplex often improves dramatically after early childhood. In some, the blisters may disappear for a short while during a feverish illness. What does epidermolysis bullosa simplex look like? The blisters of typical EB simplex look the same as the blisters that anyone can get as the result of friction to the skin. However, although they vary in size, they tend to be small (up to 2 cm) and numerous, but heal without leaving any scars. In the Dowling-Meara variant, blisters tend to occur in clusters, often healing to leave residual pigmentation. Thickened skin on the palms and soles can be a feature, especially in the Dowling Meara type of EB simplex. Thickened deformed nails may also develop. How will epidermolysis bullosa simplex be diagnosed? In older children and adults, the diagnosis of EB simplex can usually be made on the basis of the individual’s history (especially if other family members are affected) and the distribution of the blisters. Occasionally, if there is uncertainty about the diagnosis, particularly in infants your dermatologist may suggest taking a small sample of skin for more detailed microscopic examination. A blood test may be suggested to look for abnormalities of the genes likely to be involved. Can epidermolysis bullosa simplex be cured? Although during the past 20 years, there has been rapid progress in the understanding of EB simplex, at the moment it cannot be cured. There is much research worldwide in the hope of leading to an effective treatment. How can epidermolysis bullosa simplex be treated? Your dermatologist and specialist nurse will explain the best way to manage your blisters. It is generally recommended that new blisters are burst with a sterile needle, available from your doctor. In infants careful handling and application of non-sticky dressing will be required. In older children and adults often no dressing is necessary, however if one is required it is important to use a product that will not stick and damage the skin or cause further blistering when it is removed. Dressings with a silicone layer in contact with the skin are usually suitable as they are very easy to remove, and hydrogel dressings are known to help cool the blistered area and have a soothing effect. Treatments to reduce sweating of palms and soles may be of benefit. Depending on the severity, input may be required from a number of different specialists including nurses, dermatologists, paediatricians, pain specialists, podiatrists and dieticians. What can I do? Choose soft, well-fitting, comfortable leather footwear and carry a spare pair of shoes to change into later in the day. Try to keep feet cool and limit walking and manual tasks to what you know from experience are safe. Clothing should not be tight fitting. Use of antiseptic washes may help reduce the risk of secondary infection. If you have an affected child, tell their school/nursery about EB simplex and make sure they understand that your child may not be able to take part in some physical activities. If your condition is very disabling, you may be able to obtain further help with mobility by applying for personal independence payments (PIP) (see below for further information). Local authorities can sometimes provide or fund transport to school for badly affected children. If you have a car, consider applying for a disabled person’s car badge so that you can park as close as possible to your destination. This information is provided by the British Association of Dermatologists.Need to talk? Find out more about our forum and 'Ask the Expert' sessions. Donate to skin disease research.