EB in detail

Epidermolysis Bullosa (EB) is a group of inherited conditions where the skin, or mucous membranes (the lining of the mouth, gut, or eyes, for example), blister with only mild trauma, friction or even spontaneously.

It is not gender or ethnicity specific.

The genetic errors in EB result in defects in the skin proteins, because one or more of the proteins that stick the outer and deeper layers of skin together are either faulty or missing.

Over the past 15-20 years, 20 known causative genes have been found with thousands of mutations. Additional modifier genes affect severity and symptoms.

EB is not a single condition: the various types are divided into four main groups according to the depth below the skin surface at which the blisters occur:

• EB Simplex (EBS), defects in keratins 5 and 14, or plectin proteins
• Junctional EB (JEB), defects in laminins and plectin
• Dystrophic EB (DEB), defects in collagen 7 protein; Dominant dystrophic and Recessive dystrophic.
• Kindler Syndrome, mutations in the FERMT1 gene disrupting kindlin-1 protein production.

The four types, EBS, RDEB, JEB and Kindler vary widely in the type and severity of symptoms, and the impact on the patient’s life.

At present there is no cure and no treatment that makes a significant difference to patients with any form of EB. Treatment is limited to chronic wound care and pain control.

EB skin is never able to ever heal properly with normal strength: chronic open wounds and extensive scarring develop with attendant pain. Each time EB skin is damaged, the damage is irreversible, and so disfigurement and disability accrue over a lifetime. Some severe forms of EB are fatal in infancy; others in older children and young adults.

The symptoms of EB across the types include:

• Fragile skin that blisters easily, especially on the palms and feet in EB Simplex
• Itchy painful skin
• Skin loss and chronic non-healing wounds
• Nails that are thick, unformed, or absent in severe EB
• Blisters inside the mouth and throat
• Small mouth opening (microstomia)
• Difficulty swallowing
• Blistering of the airways in severe Junctional EB
• Scalp blistering and hair loss (alopecia)
• Tiny pimple-like bumps (milia)
• Dental problems, such as tooth decay
• Skin cancer