Dystrophic Epidermolysis Bullosa [DEB] is one of
the major forms of Epidermolysis Bullosa [EB]. The signs and symptoms of this
condition vary widely among affected individuals. In mild cases, blistering may
primarily affect the hands, feet, knees and elbows. Severe cases of this
condition involve widespread blistering that can lead to vision loss,
disfigurement and other serious medical problems.
Researchers classify Dystrophic Epidermolysis Bullosa
[DEB] into 3 major types. Although the types differ in severity, their features
overlap significantly and they are caused by mutations in the same gene.
Autosomal Recessive Dystrophic Epidermolysis
Bullosa —‘Hallopeau-Siemens type (RDEB-HS)’ is the most severe,
classic form of DEB. Affected infants are typically born with widespread
blistering and areas of missing skin, often caused by trauma during birth. Most
often, blisters are present over the whole body and affect mucous membranes
such as the moist lining of the mouth and digestive tract. As the blisters
heal, they result in severe scarring. Scarring in the mouth and esophagus can
make it difficult to chew and swallow food, leading to chronic malnutrition and
slow growth. Additional complications of progressive scarring can include
fusion of the fingers and toes, loss of fingernails and toenails, joint
deformities (contractures) that restrict movement and eye inflammation leading
to vision loss. Additionally, young adults with the classic form of DEB have a
very high risk of developing a form of skin cancer called ‘Squamous Cell
Carcinoma’, which tends to be unusually aggressive and is often
life-threatening.
The 2nd type of Autosomal Recessive
Dystrophic Epidermolysis Bullosa is known as the ‘non-Hallopeau-Siemens type
(non-HS RDEB)’. This form of the condition is somewhat less severe than the
classic type and includes a range of subtypes. Blistering is limited to the
hands, feet, knees, and elbows in mild cases, but may be widespread in more
severe cases. Affected people often have malformed fingernails and toenails.
Non-HS RDEB involves scarring in the areas where blisters occur but this form
of the condition does not cause the severe scarring characteristic of the classic
type.
The 3rd major type of DEB is known as
the ‘Autosomal Dominant Type (DDEB)’. The signs and symptoms of this condition
tend to be milder than those of the autosomal recessive forms, with blistering
often limited to the hands, feet, knees, and elbows. The blisters heal with
scarring but it is less severe. Most affected people have malformed fingernails
and toenails and the nails may be lost over time. In the mildest cases abnormal
nails are the only sign of the condition.
