Epidermolysis bullosa is a group of inherited disorders in which skin blisters develop in response to minor injury.
Junctional epidermolysis bullosa; Dystrophic epidermolysis bullosa; Hemidesmosomal epidermolysis bullosa; Weber-Cockayne syndrome
Causes, incidence, and risk factors:
There are four main types of epidermolysis bullosa:
- Dystrophic epidermolysis bullosa
- Epidermolysis bullosa simplex
- Hemidesmosomal epidermolysis bullosa
- Junctional epidermolysis bullosa
Another rare type of epidermolysis bullosa, called epidermolysis bullosa acquisita, is an autoimmune disorder . It may be difficult to tell this condition apart from another autoimmune skin disorder called mucous membrane pemphigoid.
Depending on the type of epidermolysis bullosa, the condition can vary from minor blistering of the skin to a lethal form involving other organs. The condition generally starts at birth or soon after. Epidermolysis bullosa acquisita, however, usually appears in adults over age 50, although it can occur in children. Also, mild cases of epidermolysis bullosa simplex may remain undiagnosed until adulthood.
Identifying the exact type of epidermolysis bullosa is complicated. Even within the main types listed above, there are many subtypes. For example, Weber-Cockayne is the most common form of epidermolysis bullosa simplex. This type involves blistering of the palms and soles and may include excessive sweating.
All of the different types of epidermolysis bullosa are generally inherited. Therefore, having a family history of the disease, and especially having a parent with it, is a risk factor. The inheritance pattern may be dominant or recessive . A dominant form means that a child can inherit the disease if only one parent has it. The recessive form means that both parents must carry a gene and transmit that gene to the child in order for child to have the disease. The recessive forms of epidermolysis bullosa tend to be worse.
The hallmark of these conditions is the formation of large, fluid-filled blisters that develop in response to minor trauma. Some infants may have large blisters at birth. Others start shortly after birth. Chafing (wearing away) of the skin, rubbing, or even increased room temperature may cause blisters to form.
In the severe forms, scarring after blister formation may cause deformities, fusion of the fingers and toes, and contracture deformities (for example, at the fingers, elbows and knees). If the mouth and esophagus are involved, blistering and scarring lead to feeding and swallowing difficulties.
Secondary infection is common.
Symptoms depend on the type of epidermolysis bullosa, but can include:
- A hoarse cry, cough, or other respiratory difficulties
- Alopecia (hair loss)
- Blistering around the eyes and nose
- Blistering in or around the mouth and throat, causing feeding difficulty or swallowing difficulty
- Blistering of the skin as a result of minor trauma or temperature change
- Blistering present at birth
- Dental abnormalities such as tooth decay
- Milia (tiny white bumps or pimples)
- Nail loss or deformed nails
For epidermolysis bullosa acquisita, there is an association with Crohn's disease (an inflammatory bowel disease) and, possibly, lupus . Adults with this type of epidermolysis bullosa may also have symptoms of these other conditions.
Signs and tests:
Your doctor may suspect epidermolysis bullosa based on the appearance of the skin.
A skin biopsy, genetic testing, and special microscopic tests of skin samples are needed to confirm the diagnosis. Immunofluorescent tests or electron microscopy is usually done on skin biopsies.
Special skin tests are used to distinguish epidermolysis bullosa acquisita in a child (which does happen on rare occasion) from other forms of epidermolysis bullosa.
Your doctor may also do a blood test to see if there is anemia. If there are wounds that are healing poorly, a culture may be done to check for bacterial infection.
If there are swallowing or feeding difficulties, upper endoscopy or an upper GI series may be done.
Growth curves will be carefully watched in an infant with, or suspected of having, epidermolysis bullosa.
If there are contractures, the range of motion of limbs will be tested.
The goal of treatment is to prevent the formation of blisters and subsequent complications. How much treatment is needed depends on how severe the disease is. Recommendations often include measures to avoid skin trauma (damage) and to avoid hot environments.
To prevent infection, excellent skin care is required, especially if any blistered areas become crusted or denuded (exposed or raw). Follow the instructions of your health care provider closely. Recommendations might include regular whirlpool therapy and applying antibiotic ointments to these wound-like areas. Your health care provider will let you know if a bandage or dressing is required, and what type.
If there are swallowing difficulties, use of oral steroids for short periods of time may be prescribed. Long term use of steroids for epidermolysis bullosa is generally not recommended. If there is candida in the mouth or esophagus, medication for that secondary infection would be prescribed as well.
Good dental hygiene is very important, including regular dental visits. It is best to be under the ongoing care of a dentist who has experience treating people with epidermolysis bullosa.
Proper nutrition is also important. When there is a lot of skin injury, you may need extra calories and protein to help recovery. Work closely with a nutritionist. When there are blisters or complications in the mouth or esophagus, avoid eating hard or brittle foods such as pretzels, nuts, and chips. Eating soft foods can help prevent making the sores worse.
Working with a physical therapist can help keep the full range of motion in the joints and minimize contractures.
Skin grafting for denuded or ulcerated areas of the skin may be necessary. Other surgical procedures for complications of epidermolysis bullosa might be recommended. Such surgeries include dilation of the esophagus if there is a stricture (narrowing), repair of hand deformities, and removal of of any squamous cell carcinoma lesions that develop.
Other treatments under investigation for epidermolysis bullosa include protein and gene therapy.
Epidermolysis bullosa acquisita may be treated with oral steroids and medication that suppresses the immune system. These may, however, increase the risk of secondary infection. Studies using interferon are also underway.
What happens depends on how severe the illness is. Mild forms of epidermolysis bullosa improve with age. Scarring from several types of epidermolysis bullosa can restrict mobility and impair daily activities. Lethal forms of epidermolysis bullosa have a very high mortality rate. (See Complications section.)
- Death -- the death rate is as high as 87% in the first year of life for infants with the lethal form of junctional epidermolysis bullosa. On the other hand, dominantly inherited simplex and dystrophic epidermolysis bullosa, and mild forms of junctional epidermolysis bullosa may not reduce life expectancy at all.
- Esophageal stricture
- Eye disorders, even blindness
- Infection, including sepsis
- Loss of function of the hands and feet
- Muscular dystrophy
- Periodontal disease
- Severe malnutrition caused by feeding difficulty, leading to failure to thrive
- Squamous cell skin cancer -- if someone with epidermolysis bullosa survives childhood, metastatic squamous cell cancer of the skin is the most common cause of death. This skin cancer occurs in those with recessively inherited dystrophic epidermolysis bullosa. Those with epidermolysis bullosa often develop this skin cancer between age 15 and 35. In addition, the skin cancer can occur anywhere on the skin. In other words, unlike in the general public, it is not more likely to happen in sun-exposed areas.
Calling your health care provider:
If your infant exhibits any blistering shortly after birth call your health care provider. If you have a family history of epidermolysis bullosa and plan to have children, genetic counseling may be appropriate.
Genetic counseling is recommended for prospective parents with a family history of any form of epidermolysis bullosa.
During pregnancy, chorionic villus sampling to test the fetus is available. For couples at high risk of having a child with epidermolysis bullosa, the test can be done as early as week 8-10 of pregnancy. Speak with your obstetrician and genetic counselor.
To prevent skin trauma and blistering, it may help to wear padding around trauma-prone areas such as the elbows, knees, ankles, and buttocks. Contact sports should be avoided.
Patients with epidermolysis bullosa acquisita who are on steroids for longer than 1 month may require calcium and vitamin D supplements to prevent osteoporosis.