Epidermolysis bullosa simplex, localized

Alternate names

EBS-loc; Weber-Cockayne type epidermolysis bullosa simplex; Epidermolysis bullosa simplex, Weber-Cockayne type; Epidermolysis bullosa simplex of palms and soles; Epidermolysis bullosa of hands and feet; Weber-Cockayne syndrome

Definition

Localized epidermolysis bullosa simplex, formerly known as EBS, Weber-Cockayne, is a basal subtype of epidermolysis bullosa simplex (EBS). The disease is characterized by blisters occurring mainly on the palms and soles, exacerbated by warm weather.

Epidemiology

• Reported prevalence ranges from 1/318,000 for localized EBS in the United States to 1/35,000 for localized EBS and non-Dowling-Meara generalized EBS (combined) in Scotland.
• About two-thirds of EBS patients have the localized basal form.

Cause

Localized EBS is caused by dominant negative mutations within either the KRT5 (12q13.13) or KRT14 (17q12-q21) genes, encoding keratin 5 and keratin 14, respectively.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

Transmission is autosomal dominant and sporadic cases are frequent.

Onset

Onset is usually in late infancy or early childhood.

Signs and symptoms

• The usual distribution of blisters in these patients is on the palms and soles, although other skin surfaces may also blister if subjected to significant trauma.
• Milia and scarring are rare in localized EBS, and dystrophic nails are uncommon.
• Focal keratoderma of the palms and soles may occur by adulthood in some patients.
• The only common extracutaneous finding in localized EBS, i.e.
• localized intraoral erosions or blisters, tends to be asymptomatic, occurs in about one third of patients, and is usually seen only during infancy.

Diagnosis

The diagnosis of epidermolysis bullosa simplex (EBS) is established in a proband by the identification of heterozygous (or rarely biallelic) pathogenic variants in KRT5 or KRT14 by molecular genetic testing; examination of a skin biopsy using immunofluorescence microscopy and transmission electron microscopy may be considered but can have limitations in the diagnosis of EBS.[1].

Treatment

• Supportive care to protect the skin from blistering
• Use of dressings that will not further damage the skin and will promote healing of open wounds.
• Lance and drain new blisters.
• Dressings involve three layers: a primary nonadherent contact layer
• A secondary layer providing stability, adding padding, and absorbing drainage; and a tertiary layer with elastic properties.[2].

NIH genetic and rare disease info

• NIH info on Epidermolysis bullosa simplex, localized

Epidermolysis bullosa simplex, localized is a rare disease.