What is epidermolysis bullosa?
Epidermolysis bullosa (EB) is a group of inherited diseases that are characterised by blistering lesions on the skin and mucous membranes. These may occur anywhere on the body but most commonly appear at sites of friction and minor trauma such as the feet and hands. Blisters may also occur on internal organs, such as the oesophagus, stomach and respiratory tract, without any apparent friction.
|Lower 3 images provided through Swinfen Charitable Trust, by Dr Taha, Erbil, Iraqi Kurdistan.|
EB should be distinguished from common friction blisters, and from epidermolysis bullosa acquisita (EBA), which is an autoimmune blistering disease that is not inherited and often doesn't develop until adult life.
The EB conditions result from genetic defects of molecules in the skin concerned with adhesion. Loss of adhesion results in blister formation. There are 3 major types of EB based on different sites of blister formation within the skin structure:
|EB Type||Site of blister formation within skin|
|Epidermolysis bullosa simplex (EBS)||Epidermis or uppermost layer of skin cells (keratinocytes)|
|Junctional epidermolysis bullosa (JEB)||Lamina lucida within the basement membrane zone (layer lying between the epidermis and dermis)|
|Dystrophic epidermolysis bullosa (DEB)||Lamina densa and upper dermis (deeper layers of skin cells)|
Within each of these types of EB there are various subtypes. Varying degrees of severity that range from mild to severe are found with each EB type.
Who gets epidermolysis bullosa?
EB is an inherited disease, which means that you have inherited one or two EB genes. In autosomal dominant EB, only one abnormal gene is needed to express the disease. This means only one parent needs to carry the EB gene. On the other hand, autosomal recessive inherited EB requires you to have two EB genes (one from each parent) to have the disease. If a person has one recessive EB gene paired with a normal gene they are called a
carrier and do not have the disease.
EB usually occurs at birth or shortly after. Males and females are equally affected. Occasionally EB may be mild enough at birth not to be apparent and it is not until the child is older or reaches adulthood before it is detected.
What are the clinical features of epidermolysis bullosa?
Epidermolysis bullosa simplex (EBS)
|EB with muscular dystrophy||
Junctional epidermolysis bullosa (JEB)
|Generalised atrophic benign EB||
|EB with pyloric atresia||
Dystrophic epidermolysis bullosa (DEB)
Prenatal testing is available for EB in some centres.
How is the severity of epidermolysis bullosa assessed?
The severity of EB can be assessed using the following scoring systems:
- The Birmingham EB score
- The EBDASI: EB Activity and Scarring Index
- The iSCOREB: instrument for scoring clinical outcomes for research of EB
- The QOLEB: Quality of life evaluation in EB
Treatment of epidermolysis bullosa
There is no cure for EB. Treatment is symptomatic and the primary aim is to protect the skin and stop blister formation, promote healing and prevent complications. Because EB can affect so many different parts of the body, a team of medical specialists is usually required for overall care. When necessary, treatment with oral and topical medications may be prescribed by your doctor to assist healing or prevent complications.
The following are some general measures used in caring for a patient with EB.
- Maintain a cool environment and avoid overheating
- Use foam padding or sheepskins to help reduce friction on furniture such as beds, chairs and infant car seats
- Wear clothing made of soft non-irritating fabrics
- Pierce, drain and dress blisters to promote healing (this should be done only by people whom have received training on wound care)
- Try to avoid using nappies in infants with severe EB, instead place child on a clean pad
- OMIM – Online Mendelian Inheritance in Man (search term Epidermolysis bullosa)
- Epidermolysis Bullosa Simplex – GeneTests GeneReviews
- Dystrophic Epidermolysis Bullosa – GeneTests GeneReviews
On DermNet NZ:
- Blistering diseases
- Epidermolysis bullosa acquisita
- Friction blisters
- Prenatal testing of inherited skin disorders
- Epidermolysis bullosa – Medscape Reference
- Epidermolysis bullosa with pyloric atresia US National Library of Medicine Genetics Home Reference
- Dystrophic epidermolysis bullosa US National Library of Medicine Genetics Home Reference
- Junctional epidermolysis bullosa US National Library of Medicine Genetics Home Reference
- Epidermolysis bullosa simplex US National Library of Medicine Genetics Home Reference
- DebRA Dystrophic EB Research Association of New Zealand
- DebRA of America Inc.
- DEBRA UK
- Australasian Blistering Diseases Foundation: including guidelines for referring a biopsy for diagnosis at the National EB Diagnostic Lab in Australia
- Asociacion de Epidermiolisis Bulosa de Chile
- Dystrophic Epidermolysis Bullosa – British Association of Dermatologists
- Epidermolysis Bullosa Simplex – British Association of Dermatologists
- Epithelial Adhesion – geneSkin