Overview Of Localized Epidermolysis Bullosa
Localized epidermolysis bullosa is one of a group of genetic conditions called epidermolysis bullosa that cause the skin to be very fragile and to blister easily. Blisters and areas of skin loss (erosions) occur in response to minor injury or friction, such as rubbing or scratching. Epidermolysis bullosa simplex is one of the major forms of epidermolysis bullosa. The signs and symptoms of this condition vary widely among affected individuals. Blistering primarily affects the hands and feet in mild cases, and the blisters usually heal without leaving scars. Severe cases of this condition involve widespread blistering that can lead to infections, dehydration, and other medical problems. Severe cases may be life-threatening in infancy.
Researchers have identified four major types of epidermolysis bullosa simplex.
Although the types differ in severity, their features overlap significantly, and they are caused by mutations in the same genes. Most researchers now consider the major forms of this condition to be part of a single disorder with a range of signs and symptoms.
The mildest form of epidermolysis bullosa simplex, known as the localized type (formerly called the Weber-Cockayne type), is characterized by skin blistering that begins anytime between childhood and adulthood and is usually limited to the hands and feet. Later in life, skin on the palms of the hands and soles of the feet may thicken and harden (hyperkeratosis).
The Dowling-Meara type is the most severe form of epidermolysis bullosa simplex. Extensive, severe blistering can occur anywhere on the body, including the inside of the mouth, and blisters may appear in clusters. Blistering is present from birth and tends to improve with age. Affected individuals also experience abnormal nail growth and hyperkeratosis of the palms and soles.
Another form of epidermolysis bullosa simplex, known as the other generalized type (formerly called the Koebner type), is associated with widespread blisters that appear at birth or in early infancy. The blistering tends to be less severe than in the Dowling-Meara type.
Epidermolysis bullosa simplex with mottled pigmentation is characterized by patches of darker skin on the trunk, arms, and legs that fade in adulthood. This form of the disorder also involves skin blistering from early infancy, hyperkeratosis of the palms and soles, and abnormal nail growth.
In addition to the four major types described above, researchers have identified another skin condition related to epidermolysis bullosa simplex, which they call the Ogna type. It is caused by mutations in a gene that is not associated with the other types of epidermolysis bullosa simplex. It is unclear whether the Ogna type is a subtype of epidermolysis bullosa simplex or represents a separate form of epidermolysis bullosa.
Several other variants of epidermolysis bullosa simplex have been proposed, but they appear to be very rare.
Commonly Associated With
EB; Junctional epidermolysis bullosa; Dystrophic epidermolysis bullosa; Hemidesmosomal epidermolysis bullosa; Weber-Cockayne syndrome; Epidermolysis bullosa simplex
Causes Of Localized Epidermolysis Bullosa
There are four main types of EB. They are:
- Dystrophic epidermolysis bullosa
- Epidermolysis bullosa simplex
- Hemidesmosomal epidermolysis bullosa
- Junctional epidermolysis bullosa
Another rare type of EB is called epidermolysis bullosa acquisita. This form develops after birth. It is an autoimmune disorder, which means the body attacks itself.
EB can vary from minor to fatal. The minor form causes blistering of the skin. The fatal form affects other organs. Most types of this condition start at birth or soon after. It can be hard to identify the exact type of EB a person has, although specific genetic markers are now available for most.
Family history is a risk factor. The risk is higher if a parent has this condition.
Symptoms Of Localized Epidermolysis Bullosa
Depending on the form of EB, symptoms can include:
- Alopecia (hair loss)
- Blisters around the eyes and nose
- Blisters in or around the mouth and throat, causing feeding problems or swallowing difficulty
- Blisters on the skin as a result of minor injury or temperature change, especially of the feet
- Blistering that is present at birth
- Dental problems such as tooth decay
- Hoarse cry, cough, or other breathing problems
- Tiny white bumps on previously injured skin
- Nail loss or deformed nails
Exams & Tests
Your health care provider will look at your skin to diagnose EB.
Tests that are used to confirm the diagnosis include:
- Genetic testing
- Skin biopsy
- Special tests of skin samples under a microscope
- Skin tests may be used to identify the form of EB.
Other tests that may be done include:
- Blood test for anemia
- Culture to check for bacterial infection if wounds are healing poorly
- Upper endoscopy or an upper GI series if symptoms include swallowing problems
- Growth rate will be checked often for a baby who has or may have EB.
Treatment Of Localized Epidermolysis Bullosa
The goal of treatment is to prevent blisters from forming and avoiding complications. Other treatments will depend on how bad the condition is.
Follow these guidelines at home:
- Take good care of your skin to prevent infections.
- Follow your provider’s advice if blistered areas become crusted or raw. You might need regular whirlpool therapy and to apply antibiotic ointments to wound-like areas. Your provider will let you know if you need a bandage or dressing, and if so, what type to use.
- You may need to use oral steroid medicines for short periods of time if you have swallowing problems. You may also need to take medicine if you get a candida (yeast) infection in the mouth or throat.
- Take good care of your oral health and get regular dental check-ups. It is best to see a dentist who has experience treating people with EB.
- Eat a healthy diet. When you have a lot of skin injury, you may need extra calories and protein to help your skin heal. Choose soft foods and avoid nuts, chips, and other crunchy foods if you have sores in your mouth. A nutritionist can help you with your diet.
- Do exercises a physical therapist shows you to help keep your joints and muscles mobile.
Surgery to treat this condition may include:
- Skin grafting in places where sores are deep
- Dilation (widening) of the esophagus if there is a narrowing
- Repair of hand deformities
- Removal of any squamous cell carcinoma (a type of skin cancer) that develops
Other treatments for this condition may include:
- Medicines that suppress the immune system may be used for the autoimmune form of this condition.
- Protein and gene therapy and the use of the drug interferon are being studied.