Junctional epidermolysis bullosa
Junctional epidermolysis bullosa generally becomes apparent at birth and may be severe. Large, ulcerated blisters are common to junctional epidermolysis bullosa and can lead to infections and loss of body fluids. As a result, severe forms of the disease may be fatal.
Epidermolysis bullosa (ep-ih-dur-MOL-uh-sis buhl-LOE-sah) is a group of rare diseases that cause fragile, blistering skin. The blisters may appear in response to minor injury, even from heat, rubbing, scratching or adhesive tape. In severe cases, the blisters may occur inside the body, such as the lining of the mouth or the stomach.
Most types of epidermolysis bullosa are inherited. The condition usually shows up in infancy or early childhood. Some people don't develop signs and symptoms until adolescence or early adulthood.
Epidermolysis bullosa has no cure, though mild forms may improve with age. Treatment focuses on caring for blisters and preventing new ones.
Epidermolysis bullosa signs and symptoms vary depending on type. They include:
- Fragile skin that blisters easily, especially on the hands and feet
- Nails that are thick or don't form
- Blisters inside the mouth and throat
- Thickened skin on the palms and soles of the feet
- Scalp blistering, scarring and hair loss (scarring alopecia)
- Thin-appearing skin (atrophic scarring)
- Tiny white skin bumps or pimples (milia)
- Dental problems, such as tooth decay from poorly formed enamel
- Difficulty swallowing (dysphagia)
- Itchy, painful skin
Epidermolysis bullosa blisters may not appear until a toddler first begins to walk or until an older child begins new physical activities that trigger more intense friction on the feet.
When to see a doctor
Contact your doctor if you or your child develops blisters, particularly if you don't know the reason for them. For infants, severe blistering can be life-threatening.
Seek immediate medical care if you or your child:
- Has problems swallowing
- Has problems breathing
- Shows signs of infection, such as warm, red, painful or swollen skin, pus, or a foul odor from a sore, and fever or chills
Basement membrane zone
Depending on the type of epidermolysis bullosa, blistering may occur in the top layer of skin (epidermis), the bottom layer (dermis) or the layer that separates the two (basement membrane zone).
Autosomal dominant inheritance pattern
In an autosomal dominant disorder, the abnormal gene is a dominant gene located on one of the nonsex chromosomes (autosomes). You need only one abnormal gene to be affected by this type of disorder. A person with an autosomal dominant disorder — in this case, the father — has a 50% chance of having an affected child with one abnormal gene and a 50% chance of having an unaffected child with two normal genes.
Autosomal recessive inheritance pattern
To have an autosomal recessive disorder, you inherit two abnormal genes, one from each parent. A carrier has one abnormal gene (recessive gene) and one normal gene (dominant gene). Carrier health is not affected. Two carriers have a 25% chance of having an unaffected child with two normal genes (left), a 50% chance of having an unaffected child who also is a carrier (middle), and a 25% chance of having an affected child with two recessive genes (right).
Epidermolysis bullosa simplex
Epidermolysis bullosa simplex usually becomes apparent at birth or during early infancy. It's the most common and least severe type. Blistering may be relatively mild with epidermolysis bullosa simplex.
Dystrophic epidermolysis bullosa
Dystrophic epidermolysis bullosa generally becomes apparent at birth or during early childhood. More severe forms of dystrophic epidermolysis bullosa can lead to rough, thickened skin, scarring, and disfigurement of the hands and feet.
Epidermolysis bullosa is usually inherited. The disease gene may be passed on from one parent who has the disease (autosomal dominant inheritance). Or it may be passed on from both parents (autosomal recessive inheritance) or arise as a new mutation in the affected person that can be passed on.
The skin is made up of an outer layer (epidermis) and an underlying layer (dermis). The area where the layers meet is called the basement membrane. The various types of epidermolysis bullosa are largely defined by which layer the blisters form in.
The main types of epidermolysis bullosa are:
- Epidermolysis bullosa simplex. This is the most common form. It develops in the outer layer of skin and mainly affects the palms and the feet. The blisters usually heal without scarring.
- Junctional epidermolysis bullosa. This type may be severe, with blisters beginning in infancy. A baby with this condition may develop a hoarse-sounding cry from continual blistering and scarring of the vocal cords.
- Dystrophic epidermolysis bullosa. This type is related to a flaw in the gene that helps produce a type of collagen that provides strength to the pig-skinlike dermis layer of the skin. If this substance is missing or doesn't function, the layers of the skin won't join properly.
Having a family history of epidermolysis bullosa is the major risk factor for developing the disorder.
Complications of epidermolysis bullosa may include:
- Infection. Blistering skin is vulnerable to bacterial infection.
- Sepsis. Sepsis occurs when bacteria from a massive infection enter the bloodstream and spread throughout the body. Sepsis is a rapidly progressing, life-threatening condition that can cause shock and organ failure.
- Fusion of fingers and changes in the joints. Severe forms of epidermolysis bullosa can cause fusion of fingers or toes and abnormal bending of joints (contractures). This can affect the function of the fingers, knees and elbows.
- Problems with nutrition. Blisters in the mouth can make eating difficult and lead to malnutrition and anemia (such as low iron levels in the blood). Problems with nutrition can also cause delayed wound healing and, in children, slowed growth.
- Constipation. Difficulty passing stool may be due to painful blisters in the anal area. It can also be caused by not ingesting enough liquids or high-fiber foods, such as fruits and vegetables.
- Dental problems. Tooth decay and problems with tissues inside the mouth are common with some types of epidermolysis bullosa.
- Skin cancer. Adolescents and adults with certain types of epidermolysis bullosa are at high risk of developing a type of skin cancer known as squamous cell carcinoma.
- Death. Infants with a severe form of junctional epidermolysis bullosa are at high risk of infections and loss of body fluids from widespread blistering. Their survival also may be threatened because of blistering, which may hamper their ability to eat and breathe. Many of these infants die in childhood.
It's not possible to prevent epidermolysis bullosa. But you can take steps to help prevent blisters and infection.
- Handle your child gently. Your infant or child needs cuddling, but be very gentle. To pick up your child, place him or her on soft material, such as cotton, and support under the buttocks and behind the neck. Don't lift your child from under his or her arms.
- Take special care with the diaper area. If your child wears diapers, remove the elastic bands and avoid cleansing wipes. Line the diaper with a nonstick dressing or spread it with a thick layer of zinc oxide paste.
- Keep the home environment cool. Set your thermostat so that your home remains cool and the temperature remains steady.
- Keep the skin moist. Gently apply lubricants, such as petroleum jelly.
- Dress your child in soft clothes. Use soft clothing that's simple to get on and off. It may help to remove labels and put clothing on seam-side out to minimize scratching. Try sewing foam pads into the lining of clothing by elbows, knees and other pressure points. Use soft special shoes, if possible.
- Prevent scratching. Trim your child's fingernails regularly. Consider putting mittens on him or her at bedtime to help prevent scratching and infection.
- Encourage your child to be active. As your child grows, encourage him or her to be involved in activities that don't cause skin injury. Swimming is a good option. For children with mild forms of epidermolysis bullosa, they can protect their skin by wearing long pants and sleeves for outdoor activities.
- Cover hard surfaces. For example, place sheepskin on car seats and line the bathing tub with a thick towel.