Epidermolysis bullosa

Author: Vanessa Ngan, Staff Writer, 2003. Updated by Jane Widdowson, EB Clinical Nurse Specialist, et al, DEBRA New Zealand, February 2016.


What is epidermolysis bullosa?

Epidermolysis bullosa (EB) is a group of inherited diseases that are characterised by blistering lesions on the skin and mucous membranes. These may occur anywhere on the body but most commonly appear at sites of friction and minor trauma such as the feet and hands. In some subtypes, blisters may also occur on internal organs, such as the oesophagus, stomach and respiratory tract, without any apparent friction.

Epidermolysis bullosa

EB should be distinguished from common friction blisters, and from epidermolysis bullosa acquisita (EBA), which is an autoimmune blistering disease that is not inherited and often doesn't develop until adult life.

The EB conditions result from genetic defects of molecules in the skin concerned with adhesion. Loss of adhesion results in blister formation. There are 4 major types of EB based on different sites of blister formation within the skin structure:

EB typeSite of blister formation within skin
Epidermolysis bullosa simplex (EBS) Epidermis or uppermost layer of skin cells (keratinocytes)
Junctional epidermolysis bullosa (JEB) Lamina lucida within the basement membrane zone
Dystrophic epidermolysis bullosa (DEB) Lamina densa and upper dermis
Kindler syndrome Mixed pattern or multiple levels within and/or beneath the basement membrane zone

Within each of these types of EB there are various subtypes. Varying degrees of severity that range from mild to severe are found with each EB type. International consensus on the diagnosis and classification of EB has resulted in updated recommendations (2014), based on newer clinical and molecular data.

Who gets epidermolysis bullosa?

EB is an inherited disease, which means that you have inherited one or two EB genes. In autosomal dominant EB, only one abnormal gene is needed to express the disease. This means only one parent needs to carry the EB gene. On the other hand, autosomal recessive inherited EB requires you to have two EB genes (one from each parent) to have the disease. If a person has one recessive EB gene paired with a normal gene they are called a carrier and do not have the disease.

EB usually occurs at birth or shortly after. Males and females are equally affected. Occasionally EB may be mild enough at birth not to be apparent and it is not until the child is older or reaches adulthood before it is detected.

What are the clinical features of epidermolysis bullosa?

Epidermolysis bullosa simplex (EBS)

EBS SubtypesFeatures
Localised EBS
Previously known as Weber-Cockayne
  • Most common and localised form of EBS
  • Blisters develop on hands and feet in response to friction
  • Usually presents in infancy as child is starting to crawl and walk
  • Wounds heal without scarring but there may be thickening of the skin on soles and palms
Generalised EBS
Previously known as Koebner
  • Generalised EBS where blisters develop all over the body but commonly on hands, feet and extremities
  • Presents at birth or early in infancy
  • May be mild involvement of mucous membranes and nails
  • Thickening of skin and plaques develop on palms and soles
Generalised severe EBS
Previously known as Dowling Meara
  • Generalised and severe form of EBS
  • Present at birth with blistering on the face, trunk and limbs
  • Thickened skin may cause calluses that limit or interfere with joint movement
  • Nails often affected
  • May involve other organs including inside the mouth, gastrointestinal and respiratory tract
  • Widespread involvement may cause death in infancy but usually there is significant improvement with age

Junctional epidermolysis bullosa (JEB)

JEB SubtypesFeatures
Generalised severe JEB
Previously known as Herlitz
  • Generalised and most severe form of JEB where blisters appear all over the body and often involve mucous membranes and internal organs
  • May only present at birth with small single blister but becoming more widespread soon after
  • Hoarse cry or cough is indicative of internal organ involvement
  • Complications such as infection, malnutrition and dehydration usually lead to early death in infancy
  • Most cases are lethal within the first 12–24 months of life
Generalised intermediate JEB
Previously known as Non-Herlitz
  • Generalised blistering and mucosal involvement present at birth or soon after
  • Scalp, nails and teeth more involved
  • Complications such as infection, malnutrition and dehydration may cause death in infancy but those who survive clinically improve with increasing age

Dystrophic epidermolysis bullosa (DEB)

DEB SubtypesFeatures
Dominant generalised DEB
  • Generalised blistering present at birth
  • Blistering becomes localised to hands, feet, elbow or knees as child grows older and in response to friction
  • Small white spots called milia are often present at healed but scarred sites
  • Bart syndrome: aplasia cutis, lesions in the mouth, and abnormal nails due to abnormal type 7 collagen in anchoring fibrils
  • May also get blistering of the oesophagus
Generalised severe recessive (R) DEB
Previously known as Hallopeau-Siemens; and;
Generalised intermediate RDEB (previously Non-Hallopeau-Siemens)
  • May present with severe blistering (generalised severe RDEB) or mild disease (generalised intermediate RDEB)
  • Generalised severe blistering is more common and involves large areas of skin and mucous membranes
  • Blisters heal but with scarring and deformity causing limited movement as fingers and toes may be fused together (mitten hands)
  • Complications such as infection, malnutrition and dehydration may cause death in infancy
  • Those that survive are at great risk of developing squamous cell carcinoma (SCC) within chronic EB wounds. SCC look and behave differently in EB than in unaffected individuals, thus a low threshold for review by a specialist dermatologist should be considered.

Kindler syndrome

Kindler syndromeFeatures
Kindler syndrome
  • Blistering and photosensitivity beginning in infancy or early childhood
  • Gradual poikiloderma (altered pigmentation) and cutaneous atrophy (wasting)
  • Trauma related blistering on hands and feet
  • Can also develop mucosal involvement, ophthalmic and dental abnormalities
  • Early development of actinic keratoses

There are many other subtypes of EB. The presentation and severity of EB is affected by the specific genetic changes and can at times be difficult to classify.

Genetic counselling and prenatal testing is available for EB in some centres, and should be considered.

A referral for psychological support for those with EB and their family should also be considered, especially for the more severe subtypes.

How is epidermolysis bullosa diagnosed?

In the dominant subtypes of EB, where an informative family tree is known, it is often acceptable for a clinical diagnosis (based on the presenting signs) to be made by a specialist dermatologist.

  • Diagnostic tests are also available in some countries and include skin biopsy of a newly induced blister which undergoes immunofluorescence antigen mapping (IFM) and/or transmission electron microscopy (EM). Mutational analysis (blood testing of genes), although not currently considered the first-line diagnostic test, is also available in some countries.

A referral to a dermatologist will be required.

How is the severity of epidermolysis bullosa assessed?

The severity of EB can be assessed using the following scoring systems:

  • The Birmingham EB score
  • The EBDASI: EB Activity and Scarring Index
  • The iSCOREB: instrument for scoring clinical outcomes for research of EB
  • The QOLEB: Quality of life evaluation in EB

Treatment of epidermolysis bullosa

General

There is no cure for EB. However, significant research, including gene therapy and cell-based therapy, continue in the aim to improve quality of life.

Most current treatment is symptomatic. The primary aim is to protect the skin and stop blister formation, promote healing, and prevent complications.

Because EB can affect so many different parts of the body, a team of medical specialists is usually required for overall care. When necessary, treatment with oral and topical medications may be prescribed by your doctor to assist healing or prevent complications.

The following are some general measures used in caring for a patient with EB.

  • Avoidance of activities that induce friction on the skin. This includes the handling of infants and children – alternative handling techniques are easily learnt from a trained health care professional.
  • Maintain a cool environment and avoid overheating
  • Use foam padding or sheepskins to help reduce friction on furniture such as beds, chairs and infant car seats
  • Choose clothing (including nappies) and footwear that is light, has no irritating seams or detail eg, zips and tight elastic.
  • Pierce, drain and dress blisters to promote healing (this should be done only by people whom have received training on wound care)
  • Many traditional adhesive tapes and dressings may be unsuitable for people with EB — especially those with the more severe forms (eg, RDEB) — as their removal can cause additional trauma to the skin. Use of advanced wound care products such as low-adherent silicone tapes and dressings is recommended. However, resourcefulness by using items readily available, such as applying additional lubrication (eg, Vaseline/paraffin oil) to some traditional wound dressings, is helpful.
  • When EB affects other parts of the body, various cares and treatments are adopted. For example, a soft diet when the oesophagus is involved, or using stool softeners for constipation, or if patient has anal blisters.
  • Clinical practice guidelines are available on the DEBRA* International website including those on Oral Health care, Wound Care, Pain Management, Cancer Management.
  • Further support and information from both health care professionals and those affected by EB:
    • DEBRA (Dystrophic Epidermolysis Bullosa Research Association) International has over 50 member groups worldwide.
    • Eb-Clinet is a clinical network or EB centres and experts across the world.

Contribute to Dermnet

Did you find this page useful? We want to continue to deliver accurate dermatological information to health professionals and their patients — for free. Funding goes towards creating articles for DermNet, supporting researchers, and improving dermatological knowledge around the world.

Donate now with credit card or Paypal

 

Related information

 

References

On DermNet NZ

Other websites