dystrophic epidermolysis bullosa

What is Dystrophic Epidermolysis Bullosa (DEB)?

Dystrophic epidermolysis bullosa (DEB) is a condition characterized by blistering of the skin and, in some cases, other areas of the body. It is caused by harmful genetic changes (variants) in the COL7A1 gene.

Individuals with DEB have very fragile skin that blisters easily in response to minor trauma, such as bumps, scrapes, or rubbing. Abnormalities of the fingernails and toenails (dystrophic nails) are also present. In some cases, an individual must have two variants in COL7A1 to develop symptoms, and this is known as "recessive DEB" (RDEB). Other individuals with only one COL7A1 variant develop symptoms, and this is called "dominant DEB" (DDEB).

There are multiple subtypes of DEB that vary in severity and in which areas of the body the blisters occur. The most common subtypes of DEB include severe, intermediate, and localized. There are also rarer forms, including the inversa, pruriginosa, and self-improving forms. Most individuals with recessive DEB will develop either the severe or intermediate form of the condition. Individuals with dominant DEB most commonly have the intermediate or localized form of the condition, though the pruriginosa or self-improving forms can also occur.

Severe

The severe form occurs in individuals with recessive DEB but does not occur with dominant DEB. In this form of the condition, blisters begin developing at birth and can be found all over the skin, mouth, throat, and eyes. Blisters can become infected and, as they heal, form scars. These scars lead to other complications, such as difficulty feeding, anemia, growth issues, vision loss, kidney issues, the fusion of the fingers and toes (pseudo-syndactyly), and loss of joint mobility (joint contractures). Babies may also be born with patches of missing skin (aplasia cutis congenita). Individuals with severe DEB are at high risk of developing squamous cell carcinoma (SCC), a type of skin cancer. SCC is often diagnosed in early adulthood, and around 90% of individuals will develop SCC by age 55.

Intermediate

In this form, blistering typically begins in the newborn period but is milder than in severe DEB, and individuals are less likely to develop complications from scarring. The risk for SCC is much lower in individuals with intermediate DEB.

Localized

Individuals with the localized form of DEB have symptoms that are limited to particular areas of the body, such as blistering of hands, feet, shins, and abnormalities of the nails.

Other rarer forms

There are several rare forms of DEB. The inversa form causes blistering that is mainly on the torso, thighs, and legs beginning at birth. Individuals with the pruriginosa form have blistering that is limited to the shins, and this may not develop until childhood or even adulthood. There is also a rare self-improving form, in which the tendency to blister improves with age.

Additional considerations for carriers

Some individuals who carry only one variant in COL7A1 have dominant DEB (DDEB). Not everyone who carries a single variant in COL7A1 will develop symptoms of DDEB. In some cases, it can be difficult to predict whether a particular COL7A1 variant will cause symptoms of DDEB. Carriers of a COL7A1 variant should speak with their healthcare provider to determine the most appropriate management options for them.

How common is Dystrophic Epidermolysis Bullosa?

The incidence of DEB in the population is between 3 in 1,000,000 – 6 in 1,000,000 births.

How is Dystrophic Epidermolysis Bullosa treated?

There is no cure for DEB. Treatment for the condition is directed at managing an individual's specific symptoms. Common interventions may include draining and bandaging blisters and giving medications to help manage pain, itching, and infections. If a fetus is known to have dystrophic epidermolysis bullosa, cesarean delivery may be recommended to avoid damage to the skin during birth. For individuals with issues related to feeding and nutrition, supplements and/or a feeding tube may be helpful.

What is the prognosis for an individual with Dystrophic Epidermolysis Bullosa?

The prognosis depends on the specific subtype and severity of DEB. Many individuals with the severe form of DEB live into young adulthood. SCC is the most common reason for early death for individuals with severe DEB. In rare cases, some infants pass away from infection. Survival is often longer for individuals with other forms of DEB, and many of those individuals have a normal life expectancy.