Epidermolysis Bullosa

Updated: Dec 12, 2016
  • Author: M Peter Marinkovich, MD; Chief Editor: William D James, MD  more...
  • Print
Overview

Background

Epidermolysis bullosa (EB) is a group of inherited bullous disorders characterized by blister formation in response to mechanical trauma. Historically, epidermolysis bullosa subtypes have been classified according to skin morphology. [1, 2]

Discoveries of the molecular basis of epidermolysis bullosa have resulted in the development of diagnostic tools, including prenatal and preimplantation testing. Based on a better understanding of the basement membrane zone (BMZ) and the genes responsible for its components, newer treatments (eg, gene or protein therapy) may provide solutions to the skin fragility found in patients with epidermolysis bullosa.

Related articles include Epidermolysis Bullosa Acquisita and Pediatric Epidermolysis Bullosa.

Next:

Pathophysiology

Epidermolysis bullosa is a family of bullous disorders caused by an absence of basement membrane components due to underlying gene mutations. Epidermolysis bullosa is classified into three major categories: (1) epidermolysis bullosa simplex (intraepidermal skin separation), (2) junctional epidermolysis bullosa (skin separation in lamina lucida or central BMZ), and (3) dystrophic epidermolysis bullosa (sublamina densa BMZ separation, as in the images below). [3, 4]

Dominantly inherited dystrophic epidermolysis bull Dominantly inherited dystrophic epidermolysis bullosa. The blistering in this disease often is localized and is characterized by scarring and milia in healed blister sites.
Dominantly inherited dystrophic epidermolysis bull Dominantly inherited dystrophic epidermolysis bullosa. This subtype, similar to other dystrophic and junctional epidermolysis bullosa subtypes, can result in nail dystrophy and loss.

 

Previous
Next:

Epidemiology

Frequency

United States

The United States National Epidermolysis Bullosa Registry [5] found the overall incidence and prevalence of epidermolysis bullosa to be 19.6 and 11.07 cases per 1 million live births, respectively. The incidence and prevalence of epidermolysis bullosa simplex were found to be 7.87 and 6 cases per 1 million live births, respectively. The incidence and prevalence of junctional epidermolysis bullosa were found to be 2.68 and 0.49 cases per 1 million live births, respectively. The incidence and prevalence of dominant dystrophic epidermolysis bullosa were found to be 2.12 and 1.49 cases per 1 million live births, respectively. The incidence and prevalence of recessive dystrophic epidermolysis bullosa were found to be 3.05 and 1.35 cases per 1 million live births, respectively.

International

According to the National Epidermolysis Bullosa Registry, [6] the prevalence epidermolysis bullosa cases in Norway is 54 cases per million live births, in Japan is 7.8 cases per million live births, in Italy is 15.4 cases per million live births, in Australia is 10.3 cases per million live births, and in Croatia is 9.6 cases per million live births.

Age

Onset of epidermolysis bullosa is at birth or shortly after. The exception occurs in mild cases of epidermolysis bullosa simplex, which may remain undetected until adulthood or occasionally remain undiagnosed.

Previous
Next:

Prognosis

Epidermolysis bullosa is a lifelong disease. Some subtypes, especially the milder epidermolysis bullosa forms, improve with age.

Infancy is an especially difficult time for epidermolysis bullosa patients. Generalized blistering caused by any subtype may be complicated by infection, sepsis, and death. Severe forms of epidermolysis bullosa increase the mortality risk during infancy. Patients with the generalized severe (previously termed Herlitz or letalis) form of junctional epidermolysis bullosa have the highest risk during infancy, with an estimated mortality rate of 87% during the first year of life. In patients with epidermolysis bullosa who survive childhood, the most common cause of death is metastatic squamous cell carcinoma (SCC), as in the image below.

Recessively inherited dystrophic epidermolysis bul Recessively inherited dystrophic epidermolysis bullosa; squamous cell carcinoma.

This skin cancer occurs specifically in patients with recessively inherited epidermolysis bullosa who most commonly are aged 15-35 years. In contrast, dominantly inherited epidermolysis bullosa simplex and dystrophic epidermolysis bullosa and milder forms of junctional epidermolysis bullosa may not affect a patient's life expectancy adversely.

One study reported that from 1979-2002, the overall age-adjusted annual mortality annual mortality rate from bullous skin diseases 0.103 death per 100,000 population (2000 US standard population). [7]

Previous
Next:

Patient Education

Education in proper nutrition and wound care is essential for the patient and family.

Previous