Epidermolysis bullosa (EB) is a rare genetic disease characterized by the presence of extremely fragile skin and recurrent
blister formation, resulting from minor mechanical friction or trauma. This condition is not contagious.
An estimated 1 out of every 50,000 live births are affected with some type of EB. The disorder occurs in every racial and ethnic group
throughout the world and affects both sexes equally.
For more information contact DebRA of America at
Contents:
Acknowledgements
Special thanks to Madeline Weiner and Kari McGrath for the preperation of this matereal and to the following for their
contributions to the manuscript " Living With Epidermolysis Bullosa" from which much of this material was adapted for the
following text. National Institutes of Health, National Institute of Arthritis Diabetes and Digestive and Kidney Diseases.
Arlene Pessar, R.N., B.S.N., Founder, Dystrophic Epidermolysis Bullosa Research Association of America, Inc., and to Anne
Brown, R.D., M.S., Director of Dietetics, Rockefeller University Hospital and a group of communications students from Rider
College, Lawrenceville, New Jersey, for their thoughtful review of the manuscript and for their contributions to the text.
We also acknowledge the help of members of the DebRA Scientific Advisory Board for their kind revisions for the updated
text, Dr. Amy Paller, Dr. Lawrence Schachner, Dr. Susan B. Mallory, Dr. Jo-David Fine, Dr. Mary K. Spraker, Dr. Daniel
Siegel, Dr. Robert Meirowitz. In cooperation with Dr. Alan R. Shalita, Dr. Sharon Glick. Special thanks to Dr. Ellen
Pfendner Clinical Laboratory Manager of the DebRA Molecular Diagnostics Laboratory and Dr Alan Moshell, Skin Disease
Program Director, EP, NIAMS for additional articles. Much gratitude to DebRA UK for their informative booklets about the
various types of EB and to their EB Nurse Specialists for their kindness, care and broad knowledge base of EB. In addition,
we would like to express our appreciation to several EB patients, family members and care givers for sharing with us their
insights into the special problems people with EB face.
The following information describes a group of genetic blistering diseases of the skin that are collectively referred to as
epidermolysis bullosa or EB. It has been written for patients, their families and friends, and health professionals to
explain briefly what we know about these disorders. In addition to outlining various approaches to treatment, this text
reviews current research in EB and related areas-research that ultimately will lead to control and possibly prevention of
these distressing afflictions.
EB Subtypes
Most forms of EB are inherited although it may also rarely arise as an acquired, autoimmune, bullous disease known as EB
Aquisita. Our focus is on the inherited forms of EB, each of which range from mild to severe and can require major
adjustments in the lifestyle of both the EB patient and his or her family.
There are three main forms of inherited EB: EB Simplex, Junctional EB and Dystrophic EB. These different subtypes are
defined by the depth of blister location within the skin layers.
Blister formation of EB simplex is within the epidermis. Sometimes EB simplex is called epidermolytic.
Blister formation in Junctional EB is seen at the level of the lamina lucida within the basement membrane
zone. Dystrophic EB or dermolytic EB is a scarring form of EB which occurs in the deeper tissue at the
level the lamina densa or upper dermis.
In severe EB, blisters are not confined to the outer skin. They may develop on the soft tissues (mucous membranes) inside
the body such as the linings of the mouth, esophagus, stomach, intestines, lungs, bladder and genitals. The extent of
tissue involvement experienced by an individual is usually determined by the severity of the disease and the subtype
present.
Testing for EB includes the following :
In order to appropriately identify the depth of blister location in the skin, a skin biopsy must be taken by a
dermatologist. This procedure includes numbing an area and taking a small sample of skin (~4mm) for examination under a
microscope.
Immunofluorescence antigenic mapping and monoclonal antibody studies are performed to detect the location
of the split in the skin and the absence of proteins (antigens) that are normally present in the basement membrane zone of
the skin. Monoclonal antibodies are used to bind to certain antigens (proteins) that are normally present in the basement
membrane zone of the skin. If specific antigens or proteins are missing, there will be an absence of staining, identifying
the missing protein and supporting the diagnosis of subtype.
Transmission electron microscopy involves the use of a high powered microscope to study the sample of skin
to identify structural defects.
Upon identification of subtype, Molecular studies (DNA analysis) may be done to identify the specific
genetic mutation and to determine the mode of inheritance (recessive vs dominant). This is helpful information in regard
to future family planning.
Once the genetic mutation is identified in a family, prenatal diagnosis of subsequent pregnancies is
possible. A sample of the chorionic villi (part of the outer membrane surrounding the fetus) can be taken in the later
part of the first trimester, or some amniotic fluid can be collected during the second trimester. The sample can then be
sent to the genetic molecular lab, where it can be matched against the previously identified mutation.
Unfortunately, knowledge of prognosis will depend on the diagnoses of the skin biopsy and the results of DNA testing.
Waiting for these results can be difficult, so it is helpful to locate measures of support. Support systems such as
family, other parents with children affected by EB and organizations such as DebRA can help alleviate the stress of certain
situations by providing resources and education to families of affected individuals and their caregivers.
How is Epidermolysis Bullosa Inherited?
Autosomal Dominant Inheritance: An autosomal dominant disorder is one in which one gene for the condition
expresses itself in an individual. A parent with an autosomal dominant form of EB has a 50:50 chance with each pregnancy
of transmitting the abnormal gene. The chance is the same whether the child is a boy or a girl, and birth order does not
make a difference. A child who does not inherit the gene for EB from an affected parent will not have the condition and
cannot pass it on.
In some instances, neither parent has EB, but the couple has a child with an autosomal dominant form of EB. In this
situation, the condition has usually been caused by a change, or mutation in the genetic material of the egg or the sperm.
When a new mutation occurs, the affected individual will have a 50:50 risk of passing the gene on in his/her pregnancies,
but his/her parents will not. They have no increased risk of having a child with EB in subsequent pregnancies.
Autosomal Recessive Inheritance: An autosomal recessive disorder is one in which a recessive
(unexpressed) gene for the disorder is passed from each parent and the two genes are paired together, causing the disorder
to be expressed in the child. If a person has one recessive EB gene paired with a normal gene, the person is “a carrier",
but does not have the disorder. If parents are each carriers of an autosomal recessive gene, there is a 25 percent chance
with each pregnancy that their children will have the disorder. Again, the sex of the child and the birth order do not
matter. An individual with a recessive form of EB will be at risk of having an affected child only if he or she has a
child with a carrier or another person with recessive EB.
How is EB Treated?
Because EB involves many systems of the body, parents and health professionals must take a team approach to the treatment
of an EB patient. Intense and total patient care often must be provided, particularly for young children. The severe forms
of EB require meticulous nursing care which is similar to that given to burn patients. Much of this care is often provided
by the parents; however, the education of all people who have contact with the patient is essential, including the primary
care physician, the dermatologist, the nurse, the pediatric dentist, the specialist in gastrointestinal (digestive)
diseases, the dietitian or nutritionist, the plastic surgeon, the psychologist or social worker, and the genetic counselor,
as well as teachers, relatives, baby sitters, and others.
Although there is no cure for EB, many complications can be lessened or avoided through early intervention. In all cases,
treatment of EB is directed towards the symptoms and is largely supportive. This care should focus on prevention of
infection, protection of the skin against trauma, attention to nutritional deficiencies and dietary complications,
minimization of deformities and contractures, and the need for psychological support for the entire family. Many persons
with milder forms have minimal symptoms and may require little or no treatment.
You may contact DebRA of America with questions or concerns:
*Please note that all medical information given by DebRA is for informational purposes only. Our information is not
intended to substitute the care and guidance given by a qualified physician. All regimens of care should be discussed with
the patient's physician. Always check with your physician prior to starting any medications or treatment regimens.
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