Dystrophic epidermolysis bullosa

Definition

Epidermolysis bullosa is a group of inherited disorders in which skin blisters develop in response to minor injury.

Alternative Names

Causes

There are four main types of epidermolysis bullosa:

• Epidermolysis bullosa simplex
• Junctional epidermolysis bullosa
• Dystrophic epidermolysis bullosa
• Hemidesmosomal epidermolysis bullosa

Another rare type of epidermolysis bullosa, called epidermolysis bullosa acquisita, is an autoimmune disorder. This may be indistinguishable from another autoimmune skin disorder called mucous membrane pemphigoid.

Depending on the type present, epidermolysis bullosa varies in severity from minor blistering of the skin to a lethal form involving other organs. The condition generally starts at birth or soon after that. Epidermolysis bullosa acquisita, however, usually appears in adults over age 50, although it has been reported in children. Also, mild cases of epidermolysis bullosa simplex may remain undiagnosed until adulthood.

The classification of epidermolysis bullosa is complicated. Even within the main types mentioned, there are many different subtypes of this condition. 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, especially an affected parent, is a risk factor. The inheritance pattern may be dominant or recessive. A dominant form means that an offspring can inherit the gene or trait from one affected parent. The recessive form means that both parents must carry a gene and transmit that gene to the offspring in order for the infant or child to be affected. The recessive forms of epidermolysis bullosa tend to be more severe.

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

Symptoms depend on the type of epidermolysis bullosa, but can include:

• Blistering of the skin as a result of minor trauma or temperature change
• Blistering present at birth
• Nail loss or deformed nails
• Blistering in or around the mouth and throat, causing feeding difficulty or swallowing difficulty
• Blistering around the eyes and nose
• A hoarse cry, cough, or other respiratory difficulties
• Dental abnormalities such as tooth decay
• Alopecia (hair loss)
• Milia (tiny white bumps or pimples)

For epidermolysis bullosa acquisita, there is an association with Crohn's disease (an inflammatory bowel disease) and, possibly, lupus. Symptoms of these conditions may be present, therefore, in adults who present with this type of epidermolysis bullosa.

Exams and Tests

Your physician may suspect epidermolysis bullosa based upon the appearance of the skin. A skin biopsy, genetic testing, and special microscopic tests applied to the skin samples are needed to confirm the diagnosis. Special skin tests also distinguish epidermolysis bullosa acquisita presenting 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 swallowing or feeding difficulties are present, upper endoscopy or an upper GI series may be performed.

In an infant with epidermolysis bullosa or suspected epidermolysis bullosa, growth curves will be followed very closely.

If contractures are present, the range of motion of limbs will be tested.

Treatment

The goal of treatment is to prevent the formation of blisters and subsequent complications. The intensity of care depends upon the severity of the disease. Recommendations often include measures to avoid skin trauma and to avoid high environmental temperatures.

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 application of topical antibiotics 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, however. If candida

Good dental hygiene is very important, including regular dental visits. It is best to be followed by a dentist with experience treating those with epidermolysis bullosa.

Proper nutrition is also important. When skin injury is extensive, increased calorie and protein intake may be necessary to help recovery. Work closely with a nutritionist. When blisters or complications are present in the mouth or esophagus, hard or brittle foods (such as pretzels, nuts, and chips) should be avoided. Eating soft foods can help prevent worsening of these lesions.

Working with a physical therapist can help maintain the range of motion of involved joint areas 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 as well. Such surgeries include dilation of the esophagus if a stricture (narrowing) is present, repair of hand deformities, and removal of squamous cell carcinoma lesions if they 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, particularly the latter drug category. Studies using interferon are also underway.

Outlook (Prognosis)

The outcome depends on the severity of the illness. Mild forms of epidermolysis bullosa improve with age. Scarring from several types of epidermolysis bullosa can restrict mobility significantly and, therefore, impair daily activities. Lethal forms of the epidermolysis bullosa have a very high mortality rate. (See Complications section.)

Possible Complications

• Infection, including sepsis
• Esophageal stricture
• Periodontal disease
• Loss of function of hands and feet
• Eye disorders, even blindness
• Muscular dystrophy
• Severe malnutrition secondary to feeding difficulty, leading to failure to thrive
• Anemia
• 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 the ages of 15 and 35. In addition, the skin cancer can occur anywhere on the skin. In other words, unlike the general public, it is not more likely to happen in sun-exposed areas.
• Death -- 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 lessen life expectancy at all.

When to Contact a Medical Professional

If your infant exhibits any blistering shortly after birth call your health care provider. If you have a family history of epidermolysis bullosa, further interaction with your health care provider or a genetic counselor may be appropriate.

Prevention

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 an offspring with epidermolysis bullosa, the test can be done as early as week 8-10 of the pregnancy. Speak with your obstetrician and genetic counselor.

To prevent skin trauma and blistering, it may help to wear padding around trauma-prone areas like elbows, knees, ankles, and buttocks. Contact sports should be avoided.

Patients with epidermolysis bullosa acquisita who are on steroids for longer than one month may require calcium and vitamin D supplements to prevent osteoporosis.