What causes epidermolysis bullosa?
EB is an inherited disease that’s passed on to a child from one or both parents. It can also appear in a patient as a new mutation that can be inherited by their children. If a child receives one normal and one gene for EB, they will be a carrier of EB, but in most cases will not develop symptoms. However, if both parents have the EB gene, their children will have a 25 to 50% (depending on the type) chance of developing EB. Parents who are close relatives have a higher chance of both having the abnormal gene.
Friction is what causes EB blisters to develop. Any trauma, no matter how small, often causes EB patients’ skin to tear and/or form blisters.
Who’s at risk for epidermolysis bullosa?
Anyone who has family members with the disease, especially one or both parents.
Are there different types of epidermolysis bullosa?
Yes, the different types are defined by the layer of skin where the blisters form. The outer layer of skin is the epidermis; the underlayer is the dermis. Between the layers, there is a “basement membrane.” Types of EB include:
- Epidermolysis bullosa simplex, the most common type, affects the outermost layer of skin (epidermis). Blisters develop on the palms of the hands and soles of the feet but usually heal without scarring.
- Junctional epidermolysis bullosa affects the basement membrane layer of skin. It begins in infancy and can be severe. Infants can have a hoarse cry due to continual blistering and scarring of their vocal cords. It often causes death due to blood infection (sepsis), malnutrition, dehydration, electrolyte imbalance or an obstructed airway.
- Dystrophic epidermolysis bullosa is related to a flaw in the gene that helps produce collagen in the inner layer of the skin (dermis). Collagen gives strength to the dermis layer. If it’s missing or not functioning correctly, the layers of skin do not join properly. Blisters occur in the inner layer of the skin.
- Dominant dystrophic epidermolysis bullosa (DDEB) is usually mild with blistering on hands, feet, elbows and knees. Other symptoms include scarring, tiny white bumps, and abnormally formed or missing nails.
- Recessive dystrophic epidermolysis bullosa is more severe than DDEB. In addition to DDEB symptoms, this type can cause malnutrition, anemia, narrowing of the throat/esophagus, retarded growth in children, webbing of the fingers or toes causing a loss of function, deformities, malformed teeth, and eye problems.
- Kindler syndrome is extremely rare, causing very fragile skin, and involving all layers of skin.