Epidermolysis bullosa (EB)

Epidermolysis bullosa (EB) is a actually a complex group of genetic conditions that results in very fragile and easy to blister skin. The skin of these patients is so delicate that it is often compared to the fragility of a butterfly wing.

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The slightest bit of friction, such as a gentle scratch, or injury results in blisters and skin erosions. These blisters are painful and under the constant attack of infection. Dystrophic epidermolysis bullosa (DEB) is one of the major forms of epidermolysis bullosa. DEB is further classified into three major types. The same gene is mutated, but the severity and specific symptoms vary widely from type and from individual to individual.

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1. Autosomal recessive dystrophic epidermolysis bullosa or Hallopeau-Siemens type (RDEB-HS)
This is the most severe type.  Infants are typically born with areas of missing skin and widespread blistering just from the trauma of normal birth.  The blistering can affect the entire inner and outer body…from mucous membranes in the mouth and lining of the digestive tract to the toes and ears.
As these blisters heal, they do not heal as you or I would. Instead, the heal with scar tissue.  The scar tissue creates a whole new set of problems. For example, as the scar tissue builds in the esophagus, it can make it very difficult to swallow food. Progressive scarring on the outer body can cause fusion of fingers and toes, creating a web like or nub like appearance; loss of fingernails and toenails; joint contractures, which can restrict movement; etc..  Once the child reaches puberty, there is also a high risk of developing the squamous cell carcinoma, an aggressive and life- threatening type of cancer.

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2. Non-Hallopeau-Siemens type (non-HS RDEB)

This type is usually less severe than RDEB-HS.  There are more subtypes under Non-Hallopeau-Siemens type (non-HS RDEB), but for a general discussion, mild cases will have blistering  that is limited to hands, feet, knees, and elbows in mild cases. More severe cases can have widespread blistering akin to RDEB-HS. The same malformation of toenails and fingernails is present. Scaring is usually involved. However, the scarring is usually not to the degree as it is in RDEB-HS.

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3. Autosomal dominant type (DDEB)

This is the milder of the types. Blistering is usually confined to hands, feet, knees, and elbows. There is some scarring as the blisters heal, but it is much less severe than the other types. Most of those affected will also eventually lose malformed fingernails and toenails.

Prevalence

As a whole, there are about 6.5 million newborns in the U.S. with dystrophic epidermolysis bullosa, with the severe autosomal recessive forms affecting fewer than 1 per million newborns.


Treatment

Dr. Alfred Lane best discusses future treatment here. Currently there is not a cure. 




What Causes DEB?

DEB is caused by mutations in the COL7A1 gene, the gene responsible for providing instructions for making a protein used to assemble type VII collagen. This particular collagen is a major component in the anchoring fibrils that anchor the epidermis (top layer of skin) to the underlying dermis. The dermis and epidermis in a normal body is much like two pieces of Velcro stuck together. As the skin experiences friction, the skin stays anchored together. But, in a person with DEB, the Velcro fibers are absent. So, it has nothing to keep it stuck together. The skin layers slip apart with friction or trauma, causing blisters and wounds to form.

Well Known Cases

Jonny Kennedy, is one of the most well known suffers of DEB. He was the subject of a documentary called, “The Boy Whose Skin Fell Off.” Jonny died from the skin cancer associated with DEB. The documentary captured the final moments of his life. 

I recently watched a National Geographic program about 13-year-old Garrett Spaulding. The story touched me deeply, as many do not realize that EB is not just about the disfiguring aspect, but this disease causes unimaginable pain. I literally cried as I watched Garrett’s mother tackle giving her son a five hour dressing change. His entire body is literally mummified with gauze, antibiotic creams, and net wrapping. See Garretts' story on the National Geographic show, Extraordinary Humans.