Epidermolysis bullosa simplex, Koebner type

Epidermolysis bullosa simplex (EBS) is characterized by fragility of the skin (and mucosal epithelia in some cases) that results in non-scarring blisters and erosions caused by minor mechanical trauma. The current classification of epidermolysis bullosa (EB) includes two major types and 17 minor subtypes of EBS; all share the common feature of blistering above the dermal-epidermal junction at the ultrastructural level. The four most common subtypes of EBS are the focus of this GeneReview: EBS, localized (EBS-loc; previously known as Weber-Cockayne type). EBS, generalized intermediate (EBS-gen intermed; previously known as Koebner type). EBS-with mottled pigmentation (EBS-MP). EBS, generalized severe (EBS-gen sev; previously known as Dowling-Meara type). The phenotypes for these subtypes range from relatively mild blistering of the hands and feet to more generalized blistering, which can be fatal. In EBS-loc, blisters are rarely present or minimal at birth and may occur on the knees and shins with crawling or on the feet at approximately age 18 months; some individuals manifest the disease in adolescence or early adulthood. Blisters are usually confined to the hands and feet, but can occur anywhere if trauma is significant. In EBS, gen intermed, blisters may be present at birth or develop within the first few months of life. Involvement is more widespread than in EBS-loc, but generally milder than in EBS-gen sev. In EBS-MP, skin fragility is evident at birth and clinically indistinguishable from EBS-gen sev; over time, progressive brown pigmentation interspersed with hypopigmented spots develops on the trunk and extremities, with the pigmentation disappearing in adult life. Focal palmar and plantar hyperkeratoses may occur. In EBS-gen sev, onset is usually at birth; severity varies greatly, both among and within families. Widespread and severe blistering and/or multiple grouped clumps of small blisters are typical and hemorrhagic blisters are common. Improvement occurs during mid- to late childhood. Progressive hyperkeratosis of the palms and soles begins in childhood and may be the major complaint of affected individuals in adult life. Nail dystrophy and milia are common. Both hyper- and hypopigmentation can occur. Mucosal involvement in EBS-gen sev may interfere with feeding, especially in neonates and infants. Blistering can be severe enough to result in neonatal or infant death.

Full text of GeneReview (by section):

Summary

GeneReview Scope

Diagnosis

Clinical Characteristics

Genetically Related (Allelic) Disorders

Differential Diagnosis

Management

Genetic Counseling

Resources

Molecular Genetics

References

Chapter Notes

Authors:

Ellen G Pfendner

Anna L Bruckner

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