The genetic disorder epidermolysis bullosa (EB) affects the skin and mucous membranes. The blisters can be painful and may lead to scarring, infection, and other complications, even from minor trauma or friction. People with EB have extremely fragile skin that blisters and tears easily. EBV can affect any part of the body, including the mouth, throat, eyes, and internal organs.
It is caused by mutations in genes that encode proteins that contribute to the structure and function of the skin. These proteins help the skin layers to stick together and resist damage.
EB simplex (EBS): The mildest type of EB, which affects the outer layer of the skin (epidermis) and causes blisters on the palms and feet.
Junctional EB (JEB): EB that affects the junction between the epidermis and dermis, leading to blisters on the skin and mucous membranes, scars, and deformities.
Dystrophic EB (DEB): A type of EB affecting the dermis and causing blisters that heal with scarring. A condition called DEB is associated with contractures, fusion of fingers and toes, and nail loss. It is associated with an increased risk of developing squamous cell carcinoma, a type of skin cancer.
Kindler syndrome: A very rare type of EB that affects all layers of the skin and causes blisters, photosensitivity, skin atrophy, and pigment changes.
A person with EB inherits the condition from their parents. The inheritance pattern can be either autosomal dominant or autosomal recessive based on the type of EB and the gene involved. Autosomal dominant inheritance requires only one copy of the mutated gene from either parent to produce the disorder. Autosomal recessive inheritance requires two copies of the mutated gene, one from each parent.
The symptoms of EB vary depending on the type, severity, and location of the blisters. Some common symptoms include:
Fragile skin that blisters easily, especially on areas exposed to friction or trauma, such as the hands, feet, elbows, and knees.
Blisters inside the mouth and throat that can cause difficulty swallowing, eating, and speaking.
Blisters on the eyes that can cause irritation, inflammation, and vision problems.
Blisters on the scalp that can cause hair loss and scarring.
Blisters on the nails that can cause nail deformity or loss.
Blisters on the genitals and anus that can cause pain, bleeding, and infection.
Blisters on the internal organs that can cause bleeding, inflammation, and dysfunction.
The blisters can also lead to secondary complications, such as:
Infection: The open wounds from the blisters can become infected by bacteria, fungi, or viruses, and cause inflammation, pus, fever, and sepsis.
Anemia: The chronic blood loss from the blisters can cause low levels of red blood cells, which carry oxygen throughout the body. This can cause fatigue, weakness, and pale skin.
Malnutrition: The difficulty in eating and absorbing nutrients from the blisters in the mouth and digestive tract can cause weight loss, growth failure, and vitamin and mineral deficiencies.
Pain: The blisters and their complications can cause chronic and severe pain that can affect the quality of life and mental health of people with EB.
Psychosocial problems: The physical and emotional impact of EB can cause stress, anxiety, depression, isolation, and low self-esteem.
The presence of blisters and a family history of EB are usually enough to diagnose EB at birth or in early childhood. Tests may be performed to confirm the diagnosis and determine the type and subtype of EB:
Skin biopsy: A small sample of skin is taken and examined under a microscope to see which layer of the skin is affected and which proteins are missing or abnormal.
An analysis of a blood sample can be used to detect mutations in the genes that cause EB. This can also be used to determine the inheritance pattern and risk of passing the disorder on to future children.
It is possible to test a fetus for EB during pregnancy if the family has a history of EB. A sample of tissue or fluid from the placenta or amniotic sac can be taken using chorionic villus sampling (CVS) or amniocentesis.
There is no cure for EB, but treatment can help manage the symptoms and prevent or treat the complications. The treatment plan depends on the type and severity of EB and may include:
Blisters and wounds need to be cleaned, dressed, and protected from infection and further damage. Special bandages, creams, and ointments may be used to promote healing and reduce scarring and pain.
To cope with pain, medications such as acetaminophen, ibuprofen, or opioids may be prescribed. Other methods, such as relaxation techniques, distraction, and counseling, may also help.
Nutrition support: A balanced diet that provides enough calories, protein, vitamins, and minerals is essential for growth and healing. Supplements, such as iron, zinc, and vitamin E, may be recommended to prevent or treat deficiencies. In some cases, feeding tubes or intravenous fluids may be required to provide adequate nutrition and hydration.
Physical therapy: Exercises and stretches may be done to improve mobility, prevent contractures, and maintain joint function. Splints, braces, or casts may be used to protect and support affected limbs. A contracture may need to be released or fused fingers and toes may need to be separated with surgery.
Surgical treatment may be needed to remove scar tissue from the cornea or correct eyelid problems. Eye drops, ointments, or artificial tears may be used to lubricate and protect the eyes from irritation and infection.
It is important to have regular dental check-ups and maintain good oral hygiene to prevent tooth decay, gum disease, and infection. It is possible to clean your teeth and mouth with soft toothbrushes, fluoride toothpaste, and mouth rinses. For missing or damaged teeth, dental implants or dentures may be needed.
People with DEB are at an increased risk of developing squamous cell carcinoma, a type of skin cancer that can be aggressive. The following measures can be taken to prevent and detect skin cancer:
Avoid sun exposure and use sunscreen, hats, and clothing to protect the skin from ultraviolet (UV) rays.
Examine the skin regularly and report any changes, such as new or changing moles, sores, or growths, to a healthcare provider.
Have regular skin biopsies to check for abnormal cells and remove them if needed.
It is impossible to prevent EB, but genetic counseling can help people with EB or a family history of the disorder understand the inheritance pattern, the risks of having or passing on the disorder, and the options for prenatal testing and family planning.
