Epidermolysis bullosa simplex 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.

Doctors usually diagnose epidermolysis bullosa by:

• Asking about family and medical history, because most types of epidermolysis bullosa are inherited.
• Completing a physical exam and closely examining the skin, which can help doctors identify where the skin is separating to form blisters.
• Performing a skin biopsy and reviewing the tissue sample using special microscopic techniques, which helps doctors identify which layers of the skin are affected and determine the type of epidermolysis bullosa you have.
• Ordering genetic testing to identify specifically which gene mutations you may have. This helps doctors diagnose the specific type and subtype of the disease. People who have genetic testing should see a specialist or genetic counselor to help them understand the test results.

Epidermolysis bullosa (EB) can have either an autosomal dominant or autosomal recessive mode of inheritance in epidermolysis bullosa simplex (EBS) and dystrophic epidermolysis bullosa (DEB). Kindler syndrome and junctional epidermalysis bullosa (with the exception of one report, to our knowledge) are autosomal recessive. The mode of inheritance in a given family is usually established by analyzing the family history (pedigree analysis).

EBS in families in which only one child is affected (and the parents are unaffected) could be either autosomal dominant (as the result of a de novo gene mutation) or autosomal recessive. A de novo dominant mutation is the more likely mode of inheritance. The two modes of inheritance can usually be distinguished based on results of immunohistochemistry testing.

The only accurate method to determine the mode of inheritance in a person with DEB is molecular genetic testing to identify the responsible mutation(s). Symptoms, severity, and other types of lab results alone are not sufficient. Until recently, mutations in the responsible gene were considered 100% penetrant (meaning that all people with mutations would be affected). However in several affected families, a person with a mutation for dominant DEB had no signs of the disease.

People with questions about the inheritance of their condition and genetic risks to themselves or family members should speak with a genetics professional.

Living with epidermolysis bullosa can be hard; however, taking steps to care for your skin to help prevent blisters from forming and getting help to cope can help.

To minimize friction, and to stop tears and blisters from forming, your health care team may recommend the following:

• Keep your skin cool. Never apply anything hot to the skin, and avoid using water higher than your body temperature when bathing.
• Wear loose fitting, soft clothing to avoid rubbing against the skin or causing friction.
• Avoid overheating by keeping rooms at a cool, even temperature.
• Apply lotion to the skin to reduce friction and keep the skin moist.
• Use sheepskin on car seats and other hard surfaces.
• Wear mittens at bedtime to help prevent scratching while asleep.

Managing and caring for epidermolysis bullosa may be hard. You may find it helpful to find a community or online support group. Some people may find it helpful to speak to a mental health professional about coping with the disease.

Patients with epidermolysis bullosa frequently have oral involvement, with blisters that form in the mouth and esophagus. In some people, these lesions are likely to cause difficulty in chewing and swallowing food and drinks. If breast or bottle feeding results in blisters, infants may be fed using a preemie nipple (a soft nipple with large holes), a cleft palate nipple, an eyedropper, or a syringe. When the baby is old enough to take in food, adding extra liquid to pureed (finely mashed) food makes it easier to swallow. Soups, milk drinks, mashed potatoes, custards, and puddings can be given to young children. However, food should never be served too hot.

In patients with oral involvement, hard or brittle foods and foods with high acid content (eg, tomatoes, orange juice) should be avoided. Ingestion of these foods may injure the mucosa and cause new lesions.

It is important for individuals with epidermolysis bullosa to consult with a dietitian who can identify high-caloric and protein-fortified foods and beverages that help replace protein lost in the fluid from draining blisters. They can suggest vitamin and mineral nutritional supplements that may be needed, and show how to mix these into the food and drinks of young children. Dietitians can also recommend adjustments in the diet to prevent gastrointestinal problems, such as constipation, diarrhea, or painful elimination.