Epidermolysis bullosa (EB) is a rare group of inherited disorders that manifests as blistering or erosion of the skin and, in some cases, the epithelial lining of other organs, in response to little or no apparent trauma. See the image below.
Ruptured bulla and newly erupted bulla of the leg in a newborn with epidermolysis bullosa simplex (EBS).
See 13 Common-to-Rare Infant Skin Conditions, a Critical Images slideshow, to help identify rashes, birthmarks, and other skin conditions encountered in infants.
More than 30 types of epidermolysis bullosa have been described, rendering categorization of the types controversial and often confusing. An international consensus meeting in Vienna, Austria in 2008 reaffirmed the following currently used names for the four major types of epidermolysis bullosa
Epidermolytic – Epidermolysis bullosa simplex (EBS)
Lucidolytic – Junctional epidermolysis bullosa (JEB)
Dermolytic – Dystrophic epidermolysis bullosa (DEB)
Multiple levels of blistering – Kindler syndrome
These major types were based on the precise ultrastructural level at which the split responsible for blistering occurs. The leading authority on epidermolysis bullosa added Kindler syndrome as the fourth major epidermolysis bullosa type in 2008 with a unique clinical phenotype—photosensitivity.
The three main types of epidermolysis bullosa were clinically and histologically delineated by the 1960s.
In the 1970s, electron microscopy revealed abnormal epidermal keratin filaments in epidermolysis bullosa simplex, disordered dermal anchoring fibrils in dystrophic epidermolysis bullosa, and defective hemidesmosomes in junctional epidermolysis bullosa. Antigens identified with immunohistochemistry in the 1980s
led to discovery of the major epidermolysis bullosa genes in the 1990s.
The identified genes include those that encode keratins 5 and 14 in epidermolysis bullosa simplex, collagen VII in dystrophic epidermolysis bullosa, and laminin 5 in Herlitz junctional epidermolysis bullosa. Toward the end of millennium, as the complex structure of desmosomes and hemidesmosomes was unraveled, the genes responsible for the rare subtypes were found, including those that encode α6β4 integrin in epidermolysis bullosa with pyloric atresia, plectin in epidermolysis bullosa with muscular dystrophy, and plakophilin in epidermolysis bullosa with ectodermal dysplasia.
During the past few years, systemic data collection and analysis have been performed on several thousands of patients with epidermolysis bullosa worldwide, and more than 1000 mutations, encompassing more than 10 structural genes, have now been documented. More has been learned about the molecular basis of epidermolysis bullosa, a group of diseases that shares clinical or molecular features with several other genodermatoses.
Eponyms associated with different forms of epidermolysis bullosa include the following:
Mendes de Costa