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.

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.