What Is Epidermolysis Bullosa

We have all got a blister from a burn at some point while experimenting in the kitchen. They are painful, irritating, and fragile. If not taken care of, they can pop open and expose our sensitive skin to all kinds of infections. But aside from burn injuries, can blisters be a part of other dermatological condition?

Indeed, they can. Epidermolyis bullosa (EB) is an inherited disease that creates blisters- on the skin surface and the internal mucus lining. These blisters may or may not be a result of minor trauma or friction, depending on the subtype.

If you or anyone you know has EB, you would have concerns about them that you need answers to. Read on to find out about the types of EB, symptoms, treatment, and related FAQs.

Overview

A newborn baby with blisters is an immediate cause for concern. Many inherited disorders such as pemphigus, bullous pemphigoid and EB are the potential reasons.¹ Infection is also a common cause for newborn blisters. Consult a dermatologist or a pediatric dermatologist at the earliest. They will start antibiotics (to avoid further infections) and send a sample of the blister fluid to identify the cause.

Types of epidermolysis bullosa

Our skin has many layers with different functions. These layers are bound to each other by specific molecules.

There are four major subtypes of EB based on the kind of molecules affected at each level.²

Figure 1 - The layers of skin

The layers of skin - from top to bottom are- the epidermis, the dermis, and the hypodermis. Each layer communicates and adheres to one another through an organised network of proteins. As seen in the above diagram - epidermolysis bullosa simplex affects the first layer, junctional EB affects the lamina lucida layer, dystrophic EB affects the sublamina densa, and Kindler syndrome affects the basement membrane and below.

Causes of epidermolysis bullosa

EB is an inherited disorder. It is caused due to a mutation in the various molecules that help in anchoring cells to one another.

It is autosomal - meaning that it is passed on from our sex chromosomes - X and Y. You can think of the inheritance pattern by imagining two manuals that hold the information on how everything in the body should be made. Individual pages of the manual are the proteins that bind the skin together. In case any pages are missing, the skin is not strong enough - and forms blisters. 

Signs and symptoms of epidermolysis bullosa

Epidermolysis bullosa simplex

Mucus membrane - skin lining the internal structures in the body

Junctional EB

Dystrophic epidermolysis bullosa (DEB)

Kindler syndrome

Management and treatment for epidermolysis bullosa

Specific treatment

There is no cure for EB but promising research in the field of cell-based therapy and gene therapy is ongoing. 

Management

This includes supportive care such as -wound care, avoiding new injuries, pain management, and avoiding complications.

This form of care is often given at a multi-speciality treatment centre or a primary dermatologist/pediatric dermatologist clinic with referrals to other speciality as needed.

• As breaks in the skin barrier invite a host of infections, proper wound care is essential. Vaseline or paraffin oil dressings, draining blisters with sterile technique, low-adhesive tapes, etc. are methods of good wound care. These are done by the caregiver at home or by a nurse’s home-visit
• Using padding and non-irritant clothing and footwear
• If internal organs are affected- the use of stool softeners or a soft diet can be adopted
• Many daily activities can be affected by EB like swallowing, using the toilet, or just moving- apart from the pain due to blisters. This requires specialized pain management with medications like acetaminophen, morphine, and ketamine, which can only be prescribed by a qualified pain management doctor
• Watching for and treatment of complications:
  • Infection: Avoid them by assuring sterile and timely wound care. Often, an antibiotic cover might be necessary
  • Dehydration: Water loss increases with open wounds. Increased oral intake or intravenous fluids might be required
  • Malnutrition: Internal blisters (like in the mouth) make swallowing painful. Additionally, chronic infection leads to poor growth in newborns and children. A nutritionist can help tailor energy requirements
  • Anaemia: Continuous open wounds can lead to chronic loss of blood. Low blood cells can further delay wound healing. Oral or intra-venous iron supplements will be given if this happens
  • Scarring: Wound healing ends with the laying down of fibrous skin that is tighter and less elastic. In case of wounds near openings like the vaginal canal, urinary canal, or mouth, this can restrict and/or narrow the opening. Such scars can be treated surgically
  • Immobility: Scarring around joints can prevent mobility. Physiotherapy can be helpful to restore mobility to daily activities
  • Skin cancer: Chronic wounds and scars often lead to skin cancer. Treatment from an oncologist (a doctor that treats cancers) will be required

FAQ's

How is epidermolysis bullosa diagnosed?

Epidermolysis bullosa is commonly diagnosed clinically. However, specific techniques like transmission electron microscopy (use of high-intensity electron microscopes), immunofluorescence antigen mapping (using fluorescent light to identify specifically affected sites), and genetic mapping (locating the individual genes) are done to confirm the diagnosis.

An appointment with a certified dermatologist and a skin biopsy will be necessary. They will first examine the skin and other parts of the body. Questions on family history such as if anyone has chronic blistering diseases are then asked. Finally, a part of the skin (biopsy) is taken for the above tests.

How can I prevent epidermolysis bullosa?

Since it is an inherited condition, epidermolysis bullosa cannot be avoided if you have a family history of the same. Nevertheless, knowing the nature of genes in both parents (dominant or recessive) and undergoing genetic counseling helps.

Is epidermolysis bullosa contagious?

EB is genetic, which means that the disease is not contagious. Hence, it is completely safe to be around an individual with EB. 

Who are at risks of epidermolysis bullosa?

You can have varying severity of EB depending on the type of gene inherited from your father and mother (based on Mendelian inheritance)

• Autosomal dominant - only one gene from either parent is enough for disease
• Autosomal recessive - two genes required -one from each parent for disease
• Carrier - one parent with a recessive gene and one normal parent (no disease, but can pass it on to the offspring)

With regard to sex, both are equally affected. Babies develop symptoms shortly after birth, while few get them in childhood/early adulthood.

How common is epidermolysis bullosa?

One in 50,000 live births suffer from this skin disorder.³

When should I see a doctor?

If a baby/child has broken skin or blisters, it is necessary to rule out EB or other blistering conditions. This is done by consulting with a pediatric dermatologist or a dermatologist.

What is the prognosis and life with EB?

The severity and outlook of each patient with EB depends on the subtype as well as other factors:⁴

• Epidermolysis bullosa simplex - The mild/moderate cases generally have a good prognosis. The severe variants of EBS are prone to early death, muscular dystrophy (progressive loss of muscle mass), or cardiomyopathy (weakened heart muscle)
• Junctional Epidermolysis Bullosa - About half of patients with junctional EB do not survive beyond one year of age, while the other half live up to 25
• Dystrophic Epidermolysis Bullosa - The outlook of individuals with DEB is similar to that of EBS, with additional risk factors of developing long-term problems like scarring, disfigurement, and/or squamous cell carcinoma
• Kindler Syndrome - Patients with Kindler syndrome have a good prognosis

What are the chances of the child developing EB if any one of the parents is affected?

This depends on the the inheritance pattern, i.e.- autosomal dominant or autosomal recessive as described above. The probability is as follows:

• Autosomal dominant - Only one abnormal gene from either parents is sufficient to develop disease in the child. Hence, with each pregnancy, there is a 50% chance of the child having EB
• Autosomal recessive inheritance - Two abnormal copies of the gene are required - one from each parent. If a parent has one copy of the gene and is completely healthy, he/she is a carrier of EB. In this case, with each pregnancy, there is a 25% chance of the child having EB, 50% chance of the child being a carrier, and 25% probability of the child being completely genetically normal with respect to EB

Genetic counseling will help with further evaluating the probabilities according to the individual genetic makeup of each parent and discussing the options for pregnancy.

Summary

Epidermolysis bullosa is a rare dermatological illness affecting around 1 in 50,000 individuals worldwide that causes blistering of superficial and/or internal skin lining. It starts at birth or early childhood. There are four major types of EB, and the presentation and outlook of patients depend on the subtype. Current practice of management is supportive care while avoiding further blistering.

A team-based approach with a dermatologist, pediatric dermatologist, gastroenterologist, nursing staff, and pain management specialist is required. Complications like infection, malnutrition and dehydration should be avoided and treated promptly. Newer research and advanced treatments like gene therapy are well on the way to improving patient care.