Epidermolysis Bullosa or EB is a rare and genetically inherited disorder of the skin, characterised by severe and recurrent blistering of the skin in response to minor trauma or friction as two layers of the skin, the dermis and epidermis, do not stick together properly.
In most cases, the onset of EB is at birth or shortly after. Those born with EB have skin so fragile they are often referred to as ‘butterfly children’.
The most significant problem in EB is the life-long presence of blistering, wound infections and partially chronic wounds resulting in pain, scarring and immobility. Dressing changes to treat these wounds can take several hours each day and are extremely painful, often requiring the use of opioid drugs to manage the pain.
A large percentage of the body, including mucous membranes can be affected by wounds, resulting in broad physiological effects on the body including oesophageal strictures, nutritional problems, anaemia requiring transfusions, renal impairment, osteoporosis with bone fractures and decreased mobility.
AP101 (Oleogel-S10) is being developed as a prescription medicine for EB, for which there are severely limited treatment options. It is currently in an investigational global Phase III clinical trial for this indication; however, it has already been approved in Europe for use in the treatment of partial thickness wounds (PTW) in adults.
It is estimated that there are more than 500,000 people living with EB worldwide. There is currently no known cure for EB.
Disease severity differs greatly depending on the type/sub-type of EB. The condition has been divided into four main types depending on the depending where in the skin the problem occurs:
Although often life-altering, this is the most common subtype of EB, causing mild to moderate disease. There is limited blistering, sometimes just restricted to the hands and feet, and there is little disease effects other than the skin.
DOMINANT DYSTROPHIC AND RECESSIVE DYSTROPHIC EB:
These are more severe than EB Simplex.
Dystrophic EB (DEB) derives from the tendency of the blisters to heal with scarring. This process can lead to contraction of the joints, fusion of the fingers and toes, contraction of the mouth membranes and narrowing of the oesophagus.
There is a high chance of recessive DEB sufferers developing squamous cell carcinoma of the skin before the age of 35. The majority of DEB patients are managed by specialised centres.
JUNCTIONAL EPIDERMOLYSIS BULLOSA (JEB):
JEB is a rare form of EB and is diagnosed in approximately 1% of EB cases. JEB has a broad spectrum of severity from the extreme form of generalised severe JEB (formerly known as JEB – Herlitz) with an estimated mortality rate of 87% during the first year of life, to very mild forms often diagnosed later in life.
This is an ultra-rare subtype of EB, where blistering and photosensitivity (sensitivity to light) begins in early childhood. The blistering typically reduces with age; however, skin changes (poikiloderma) and photosensitivity persist.