Epidermolysis bullosa

Epidermolysis bullosa (EB) is a group of rare genetic medical conditions. Epidermolysis bullosa simplex (EBS) is the most common form. It results in easy blistering of the skin and in severe cases also the mucous membranes (nose, mouth, and throat). Severity can range from mild (intermediate) to severe, and affect specific parts of the body (localised) or the entire body (widespread). Those with mild cases may not develop symptoms until they start to crawl or walk.

A child with EB might have inherited the faulty gene from a parent who also has EB. Or they might have inherited the faulty gene from both parents who are just "carriers" but don't have EB themselves. The change to the gene can also happen by chance, when neither parent are carriers (called de novo mutations).

There are multiple types of EB, which all effect the person differently or may share symptoms between different types. Within each type, there are different forms (such as a type of EB, Epidermolysis bullosa simplex (EBS), having different forms). Each person with the condition can still experience different symptoms within each form or type. 

 Types of epidermolysis bullosa 
The 3 main types of EB are EBS, JEB, and DEB. There are also many variants of these 3 main types of EB, each with slightly different symptoms. Symptoms might be different between each person even when the type of EB is the same. 

 Epidermolysis Bullosa Simplex (EBS) 
The most common type. It can range from mild, with a low risk of serious complications, to severe.  

Localised EBS is the most common form of EBS. It causes blisters to form (such as on the hands and feet) after physical exercise. These blisters may be caused or made worse by friction, sweat. Because of this, symptoms of localised EBS might be made worse during hot weather, such as in summer, especially if the person sweats a lot. Blisters can also develop on other parts of the body, such as the buttocks or inner thighs, after the skin has rubbed during activities like cycling. The blisters usually heal without scarring.    

Symptoms can start anytime from early childhood to adulthood. Some adults with localised EBS might get thickening of the skin on their palms and the soles of their feet, as well as thickened fingernails and toenails.   

The intermediate EBS form causes blisters to appear on the skin all over the body in response to friction or trauma. Like the blisters in other EB types they can be worse because of weather, when it is hot. Scarring, and white spots (milia) might appear on the skin. This more serious form of EBS can cause blistering of the mucous membranes. 

As with localised EBS, adults may experience thickening of the skin on their palms and the soles of their feet, as well as thickened fingernails and toenails. 

EBS severe causes blistering all over the body. In some cases a child may develop up to 200 blisters in one day. The widespread blistering can make the skin less safe where infection might happen and affect an young babies (infant) normal feeding pattern, which means they may not grow and develop well or as fast as they should.  

When an infant with severe EBS is reaching the age where they start learning to do more, like walking or eating solid food, their condition may affect them in a lot of ways. Painful blisters on the soles of the feet can affect an infant's ability to walk and may mean they start to walk later. If blisters develop in their mouth, eating and speaking will often be painful and more difficult. Thickening or loss of the fingernails and toenails is another common symptom. 

The symptoms usually develop at birth, but the blistering gradually improves as the child gets older, so adults may only sometimes experience blistering. But it's common for the skin of the palms and soles to become progressively thicker with age, and this may make walking or using the hands difficult or painful.    

 Dystrophic Epidermolysis Bullosa (DEB)  
Can range from mild to severe. 

Dominant DEB causes blistering at places on the body that experience trauma or use (often the hands, feet, arms and legs), which usually results in scarring. Milia (tiny white spots) often form at the site of the blisters. 

The nails usually become thickened and abnormally shaped, or even lost altogether. The mouth is often affected, which can make eating or cleaning teeth painful. Some people with dominant DEB have mild symptoms with very few blisters, and the only sign of the disease may be misshapen or missing nails. 

The symptoms of dominant DEB usually develop at birth or shortly afterwards, but may not start until later in childhood. 

Recessive DEB can be one of the most severe types of EB. It can cause severe and widespread skin blistering that leaves areas covered with ulcers which don't go away.  

Repeated scarring to hands and feet can result in the loss of nails. Spaces between fingers and toes can fill with scar tissue, so hands and feet take on a mitten-like appearance. 

Extensive blistering can also develop on the mucous membranes, particularly inside the mouth, oesophagus (tube connecting the mouth and stomach), anus (bottom) 

Very fragile gums and blisters or scarring in and around the mouth may cause problems with speaking, chewing and swallowing. Repeated blisters on the scalp may also reduce hair growth. 

As a result, many children with this form of DEB will have anaemia, malnutrition, and delayed or reduced growth. 

The eyes can also be affected by blistering and scarring, which is painful and can lead to vision problems. 

The symptoms of recessive DEB are usually there at birth. There may be areas of missing skin at birth, or blistering developing very shortly afterwards. People with this type of DEB have a high risk of developing skin cancer.  

Awareness of this problem and frequent check-ups (possibly twice a year) with a dermatologist are recommended. 

 Junctional Epidermolysis Bullosa (JEB) 
Ranges from moderate to severe. 
The type reflects where on the body the blistering takes place and which layer of skin is affected.

Intermediate JEB causes widespread blistering of the skin and mucous membranes and sometimes the eyes and some internal organs.

Blistering of the scalp is common, and may lead to scarring and permanent hair loss. Other symptoms include slow-healing injuries, especially of the lower legs, deformity or loss of fingernails and toenails, changes to skin colour that look like large and irregular moles, and possible scarring of the skin. 

In people with intermediate JEB, the mouth is also affected. Blisters and ulcers may form a lot which may make eating difficult while they are there. Also, tooth enamel isn't properly formed, which means teeth may be discoloured, fragile and prone to tooth decay. 

Some patients also develop problems with their urinary system, such as blistering or scarring of the tube that carries urine out of the bladder (the urethra).

The symptoms usually develop at birth or shortly afterwards and can improve with age. As adults, people with this form of EB have an increased risk of developing skin cancer, so regular review by a skin specialist (dermatologist) familiar with EB is recommended.

Severe JEB is one of the most severe types of EB, but it's extremely rare. It causes widespread blistering of the skin, mucous membranes and internal organs.

Some parts of the body are affected by blisters and ulcers. Specifically the genitals and buttocks, around the nose and mouth, fingertips, toes, and neck, inside the mouth and throat, and the eyes. 

Complications of severe JEB include: anaemia, tooth decay, malnutrition and delayed growth, dehydration, breathing difficulties, sepsis. Because of these complications, the outlook for children with severe JEB is very poor. Many babies with severe JEB don't live more than a few months.

 Symptoms and diagnosis 
EB is usually diagnosed in babies and young children. If it is suspected that a child has the condition they will be referred to a dermatologist. Some signs might not show up until later life (including adulthood). Common signs and symptoms in all types of EB include:
 skin that blisters easily
 blisters on the hands and soles of the feet
 thickened skin that may be scarred or change colour over time
 thickening of the skin and nails

Genetic testing can also find the faulty gene causing EB, alongside other genetic conditions. This is usually done in the 11th week of pregnancy. When it is a risk that an unborn baby might have the condition, genetic counselling and advice is given to the parents. 

A dermatologist will take samples of the skin to test. 

 Support  
http://www.debra-international.org/ - DEBRA International is a worldwide network of national groups working on behalf of people affected by EB.

https://cure-eb.org/ - Cure EB is a charity that funds research into treatments and a cure for Epidermolysis Bullosa. 

References

Category:Genetic disorders