Epidermolysis bullosa (EB) is caused by a fault, or mutation, in the keratin or collagen gene, and it affects the connective tissues.
Three main types of EB might occur, and previous research suggests that 6.5 in every 1 million newborns in the United States may have one of these types
The risk is the same regardless of gender and ethnicity.
People with EB have extremely fragile skin. Even very slight friction may cause blisters, as the layers of skin move independently and separate.
No cure for EB is currently available. Treatment focuses on relieving the symptoms of pain, infection risk, and complications.
Effects on the body
EB causes the skin to blister easily.
Healthy human skin has two layers:
- the epidermis, which is the outer part
- the dermis, which is the inner part
Usually, protein anchors exist between the layers. These anchors consist of collagen and prevent the two layers of skin from shearing, or moving independently from one another.
People with EB do not have these protein anchors, so when any friction occurs on the skin, the two layers rub against each other and separate. This results in painful sores and blisters.
The blistering can also occur in the mucous membranes inside the body, such as in the mouth and esophagus. Sometimes, this makes it almost impossible to eat solids. EB can also affect the urinary tract and bladder, making it painful to urinate.
Doctors often refer to younger people with EB as "butterfly children" because their skin is as fragile as the wings of a butterfly.
EB can range in severity from mild to life-threatening. In mild EB, the blistering tends to develop around the hands and feet. Severe EB often affects the whole body, and some complications, such as infection, feeding difficulties, and loss of nutrients through the skin, can be fatal.
When someone has EB, wounds heal very slowly. This can cause significant scarring, physical deformity, and disability. People with severe forms of EB have a significantly higher risk of developing skin cancers.
Three major types of EB occur:
- The most common type of EB is epidermolysis bullosa simplex (EBS). Blisters form on the outer layer of the skin.
- In dystrophic epidermolysis bullosa (DEB), blisters form on both the outer and inner layers of skin.
- Junctional epidermolysis bullosa (JEB) is the most severe form. However, it is also rare. Blisters form where the outer and inner layers of skin meet.
Each type has several subtypes. So far, medical experts have identified over 30 subtypes of EB.
Alopecia is a possible symptom of EB.
A person with EB has extremely fragile skin that incurs damage at the slightest touch. Even the gentlest rub, bump, or knock can cause blisters. Clothing that touches or rubs against the skin can also increase the risk of blistering.
In very mild presentations, a person may not develop symptoms until later in life. When blisters do occur, they may heal with minimal or no scarring.
The specific signs and symptoms depend on the type of EB a person has. They typically include:
- blistering on the skin, scalp, and around the eyes and nose
- tearing of the skin
- skin that looks very thin
- skin that falls off
- alopecia, or hair loss
- milia, or very small, white bumps on the skin
- loss of fingernails, toenails, or both, or deformity of the nails
- blisters or erosions of the eye
- excessive sweating
If EB occurs in the mucous membranes, it can cause:
- difficulties with swallowing, if blistering occurs around the mouth and throat
- a hoarse voice, due to blistering in the throat
- breathing problems, because of blistering in the upper airway
- painful urination that results from blistering in the urinary tract
Symptoms typically develop very early in a person's life, often soon after birth. In Kindler syndrome, a rare subtype of EB, blisters form at birth.
The National Institutes of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) suggest the following measures to protect the skin and prevent blistering on the skin in babies, children, and adults.
- wearing clothing that does not rub or irritate, such as clothing made from pure cotton fabrics
- using lubricants on the skin to reduce friction
- keeping room temperatures cool to prevent overheating
- covering hard surfaces, such as car seats, with sheepskin
- wearing mittens while sleeping to prevent damage caused by scratching
It is essential to cuddle all babies and young children, and following these suggestions will make it safe to cuddle a baby with EB by helping to protect the child's skin from damage. To protect the baby from further discomfort, pick it up by placing one hand under the child's buttocks and the other behind its back.
A person with EBS can prevent blisters from developing on their feet by avoiding long walks. Those with DEB or JEB should be extremely careful to avoid scratches and knocks to the skin.
Avoiding spicy foods and hard, sharp food items that may cut and scratch, can protect blisters or reduce pain in the mouth.
Make sure that eyeglasses do not cause blistering around the nose and ears.
Faulty genes cause EB. A person might inherit these from one or both parents.
To pass on JEB, both parents must have the faulty gene. For all other types, only one parent needs to have it.
In other cases, the fault might occur during the formation of the egg or sperm.
Most experts believe that the mutation occurs in the keratin or collagen gene.
A biopsy can help identify the type of EB.
Doctors diagnose most people with EB during infancy. Sometimes, however, when symptoms are mild, doctors do not make a diagnosis until later on in a person's life.
Doctors may carry out a variety of other diagnostic tests for EB, including:
- A biopsy in which the doctor takes a small sample of skin tissue for analysis. This can show where the skin is separating, and what kind of EB the person has.
- A microscope and reflected light, which can reveal whether any of the proteins necessary for forming the connecting tissues are missing.
- A high-power electron microscope that can identify structural defects in the skin.
- Blood tests. A doctor can test blood samples from an individual with suspected EB. They may also take blood from people to check for genetic issues. This will also help identify whether a person has inherited the condition from a parent.
- A doctor can carry out an amniocentesis test during pregnancy. Amniocentesis involves removing and examining a small amount of the amniotic fluid that surrounds the fetus.
- A doctor may also consider chorionic villus sampling (CVS), which involves testing part of the membrane that surrounds the fetus.
No cure for EB is currently available. Treatments focus on symptom relief and preventing skin damage, infections, and other complications.
Some people may also require psychological and emotional support to help them maintain a good quality of life.
- The doctor may teach people how to break any large blisters safely and hygienically. Skillful puncturing can enable the fluid from a blister to drain without increasing the risk of infection or damaging the skin underneath.
- The doctor may prescribe a topical antibiotic for an infection.
- Wound dressings should not stick to the skin, so doctors may recommend specific types of bandage to aid healing, reduce pain, and lessen the chance of infection.
- If a lesion does not heal completely, a skin graft may be necessary. Covering the wound with skin may help the healing process.
- Repeated, severe blistering and scarring can cause fingers to fuse. Also, muscle tissue might shorten abnormally, making it hard for a person to carry out everyday tasks. In these situations, surgery may be necessary.
- Pain is a major symptom of EB, so treatment typically involves pain control medication.
- If blistering in the esophagus makes eating difficult, the doctor may recommend surgery to widen the esophagus.
- If a person with EB cannot swallow food, they may need a gastrostomy tube. The surgeon makes an opening into the stomach and passes a feeding tube through it.
Some people with EB may develop severe complications.
- Blisters might lead to infection and open sores.
- People with DEB have a higher risk of developing squamous cell carcinoma, which is an aggressive form of skin cancer, before the age of 35 years.
- Sometimes, DEB causes a person's fingers to fuse.
- If EB affects the conjunctiva and other parts of the eye, some people may experience vision loss.
- If an individual cannot swallow easily, they may develop malnutrition.
- Anemia may develop, due to chronic inflammation and blood loss.
Some of the complications of EB, such as dehydration, infection, internal blisters, and malnutrition can be fatal, especially in young infants.
Can EB develop from other conditions or is it solely genetic?
Other conditions cannot convert to EB. Epidermolysis bullosa is a genetically inherited disorder. Sometimes, one parent has the gene and experiences the condition themselves. This person has a 50 percent chance of passing EB onto their child.
In other cases, both parents may carry the gene without being aware of it. In these situations, there is a 25 percent chance that a child will develop the disorder.
Occasionally, a child can develop EB when neither parent carries the gene, but a gene in the egg or sperm mutates.J. Keith Fisher, M.D. Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.