Dystrophic epidermolysis bullosa - Skin
DEB is subclassified into two major subtypes, based on its mode of inheritance: autosomal dominant DEB (DDEB) and recessive DEB (RDEB). Further subclassification is based on overall severity, clinical phenotype, ultrastructural and antigenic findings, and genotype. Although some DEB subtypes may eventually be clinically localized to specific anatomic sites (ie, acral, pretibial) or have unusual distributions (ie, inverse, centripetal), each may be generalized at birth or during infancy, and some rarely may be life-threatening. In addition to blisters, erosions, and crusts, other common cutaneous findings include atrophic scarring, milia, and nail dystrophy. Scarring alopecia of the scalp may also occur.
Extracutaneous complications are common among patients with DEB, most notably those who have severe generalized RDEB (sev gen RDEB, formerly known as Hallopeau Siemens RDEB). The extent and severity of these complications varies among DEB subtypes. Virtually every organ lined or surfaced by epithelium may be involved, with clinical findings present as early as within the first year of life. The most common organs or sites involved include the external eye, oral cavity, esophagus, genitourinary tract, lower gastrointestinal tract, hands and feet, and bone marrow. Patients with sev gen RDEB are also at some risk of renal failure and dilated cardiomyopathy, either of which may prove fatal. External eye manifestations include but are not limited to painful blistering, erosions, and scarring of its surface, which may lead to blindness. Oral findings include microstomia, soft tissue scarring of the oral cavity and tongue, and severe secondary caries formation, leading to premature loss of teeth. Gastrointestinal complications include stenosis, strictures, or webbing within the esophagus, chronic erosions within the small intestine (contributing to chronic malabsorption and malnutrition), constipation, GERD, and painful anal fissures. Anemia, seen primarily in sev gen RDEB, is multifactorial and is usually severe. Marked growth retardation is also the norm in severely affected RDEB patients, as is delayed puberty. Progressive mutilating webbing of the fingers and toes (pseudosyndactyly) is common in RDEB, leading to deformities that may grossly impair use of the hands and limit ambulation.
Blistering is invariably worse in all EB patients during warm weather and may be exacerbated by concurrent systemic illnesses, including infection.
Death may occur in infants and young children with sev gen RDEB, mainly as a result of sepsis. The vast majority of patients with RDEB, though, most notably those with sev gen RDEB, develop at least one cutaneous squamous cell carcinoma (SCC) during their lifetime. Although these SCCs are typically histologically well differentiated, most of these patients subsequently die of metastases from some SCC within 5 years of the diagnosis and apparent successful surgical excision of their first SCC. Although RDEB-associated SCCs may very rarely arise in childhood, most do not arise until after the middle or end of the second decade of life, after which time there is an increasingly steep rise in the cumulative risk of a first SCC developing.
For more information on the autosomal dominant subtype, see OMIM.
For more information on the autosomal recessive subtype, see OMIM.
Q81.2 – Epidermolysis bullosa dystrophica
254185007 – Dystrophic epidermolysis bullosa
- Other types and subtypes of inherited EB (EB simplex; EB simplex, Dowling-Meara; junctional EB)
- Ectodermal dysplasia, including
- AEC syndrome (ankyloblepharon-ectodermal dysplasia-cleft lip/palate)
- EEC syndrome (ectrodactyly-ectodermal dysplasia-cleft lip/palate)
- Incontinentia pigmenti
- Bullous mastocytosis
- Acrodermatitis enteropathica
- Neonatal herpes simplex
- Bullous impetigo
- Cutaneous porphyrias