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Epidermolysis Bullosa

Junctional EB

Dystrophic EB

 

 

 

 

 

 

 

 

 

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 ďa 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.

 

 

 

 

 

 

Created By Jennie

 *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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