Epidermolysis bullosa
Epidermolysis bullosa is a family of rare skin diseases that cause skin fragility and blisters due to friction.
What is epidermolysis bullosa?
Epidermolysis bullosa (EB) - also called the “butterfly skin disease” - is a group of rare diseases with skin fragility characterized by structural anomalies that reduce the resilience of skin, causing painful, open wounds that appear due to friction. The blisters may appear in these patients in response to a minor injury, even from heat, rubbing, scratching or adhesive tape. In severe cases, blisters may occur inside the body, such as the lining of the mouth or the stomach.
The four major kinds of epidermolysis bullosa are EB simplex -the most common kind, developed in the outer layer of skin-, junctional EB -characterized by blisters between the dermis and the epidermis, it affects skin and mucosa and can be severe-, dystrophic EB -related to a flaw in the gene collagen VII, which helps produce a protein that glues dermis and epidermis together- and Kindler syndrome.
It tends to cause blisters in different skin layers, so it can look very different from person to person. The condition usually shows up in infancy or early childhood. Some people do not develop signs and symptoms until adolescence or early adulthood.
Currently, the overall prevalence of the different kinds of EB is approximately 11 affected subjects per one million people.
What causes epidermolysis bullosa?
Epidermolysis bullosa has a genetic origin. The disease gene may be passed on from one parent who has the disease (autosomal dominant inheritance), or it may be passed on from both parents that are carriers (autosomal recessive inheritance) or arise as a new mutation in the affected person that can be passed on. For example, dystrophic EB may be inherited as a dominant or recessive trait; generally, the recessive form, RDEB, is more severe than the dominant disease, DDEB.
The skin is made up of an outer layer (epidermis) and an underlying layer (dermis). The area where the layers meet is called the basement membrane. The various types of epidermolysis bullosa are largely defined by which layer the blisters form in .
How to detect epidermolysis bullosa?
Patients with epidermolysis bullosa have fragile skin that blisters very easily. At the slightest trauma, lesions occur in the form of blisters that form scars when they heal. These are usually very prominent and complex and may entail retraction of the surrounding skin. Blisters or lesions may appear all over the body, on the outer layer of the skin, but also in the mucosa, such as the mouth, the nose, the eyes, etc.
In the most severe versions of the disease, scarred lesions may reduce the size of the mouth, limit the opening of the eyes, or even join fingers or toes together. Internal lesions may also occur, such as in the esophagus, preventing a proper diet and therefore leading to malnutrition. This type of scar must be clinically treated to be stabilized and/or reduced as much as possible.
On the contrary, patients with less severe variants usually suffer localized blisters mainly on hands, feet, knees, elbows, or the trunk, and often without the extreme scarring observed in more severe cases. Dystrophic nails, particularly toenails, are common and usually the most obvious manifestations in these cases.
A doctor may suspect epidermolysis bullosa from the appearance of the affected skin. Some laboratory tests may be needed to confirm the diagnosis, which may include a skin biopsy or a genetic test.
How to prevent epidermolysis bullosa?
It is not possible to prevent epidermolysis bullosa, but some actions can be taken to prevent blisters and infections.
- Handle your child gently.
- Take special care with the diaper area.
- Keep the home environment cool.
- Keep the skin moist.
- Dress your child in soft clothes.
- Prevent scratching.
As your child grows, encourage him or her to be involved in activities that do not cause skin injury. Swimming is a good option. For children with mild forms of epidermolysis bullosa, they can protect their skin by wearing long pants and sleeves for outdoor activities.
A C-section birth is recommended in those cases where the diagnosis is previously known.
How to treat epidermolysis bullosa?
Currently, epidermolysis bullosa can be treated with a topical anti-inflammatory cream or topical gene therapy. In addition, it is important to treat its symptoms (blisters and lesions). Blisters must be drained and covered with padded, non-adherent materials, usually wrapped in elastic bandages. In most severe cases, it is important to monitor patients' malnutrition and growth and, if necessary, supplement or modify their diet.
Due to these patients' increased risk of developing squamous cell carcinoma, it is important to monitor abnormal-looking lesions that do not heal or have abundant scar tissue, especially after age 20. Furthermore, it is recommended to conduct annual ECGs to identify heart conditions, and bone mineral density studies to identify osteoporosis.
References
- Debra Org. EB in Depth. 2020 January [Revised 2020 March]. Available at: https://www.debra.org/about-eb/eb-depth
- Mayo Clinic. Epidermolysis Bullosa. 2018 March [Revised 2020 March]. Available at: https://www.mayoclinic.org/diseases-conditions/epidermolysis-bullosa/symptoms-causes/syc-20361062
- Medline Plus. Epidermolysis Bullosa. 2018 October [Revised 2020 March]. Available at: https://medlineplus.gov/ency/article/001457.htm
- Fine JD. Epidemiology of Inherited Epidermolysis Bullosa Based on Incidence and Prevalence Estimates From the National Epidermolysis Bullosa Registry. JAMA Dermatol. 2016 Nov 1;152(11):1231-1238. doi: 10.1001/jamadermatol.2016.2473. PMID: 27463098.
- Has C. et al. Consensus reclassification of inherited epidermolysis bullosa and other disorders with skin fragility. Br J Dermatol. 2020 Oct;183(4):614-627. doi: 10.1111/bjd.18921. Epub 2020 Mar 11. PMID: 32017015.