Epidermolysis Bullosa

ICD-11

EC30, EC3Z, EB43

Epidemiology

0.2 in 100000 live births worldwide; estimated 500000 cases worldwide. (Orphan disease). Epidermolysis bullosa simplex the most common sub-type of epidermolysis diseases (>90%).

Definition

Group of genetic diseases with skin fragility in which minimal trauma leads to the formation of blisters; autosomal dominant and autosomal recessive inheritance.

Aetiology & Pathogenesis

Mutations in structural proteins and adhesive complexes of the epidermis and the epidermal-dermal junction.

Signs & Symptoms

Blisters heal with or without scars, depending on the level of the defect (mutilations). With widespread disease, disturbances in electrolyte, water and protein balance. With oral and gastrointestinal tract involvement with life threatening scarring, difficulty eating and failure to thrive.

Localisation

Every part of the body can be involved, predilection to areas exposed to pressure and friction.

Classification

Several subtypes depending on location of defective protein and level of blister formation in the skin. Clinically mild and severe forms of epidermolysis bullosa simplex, junctional epidermolysis bullosa and/or dystrophic epidermolysis bullosa.

Laboratory & other workups

Dermatopathology, immunofluorescent antigen mapping, electron microscopy, DNA sequencing of candidate genes.

Dermatopathology

Epidermolysis bullosa simplex: intraepidermal cleavage (keratin 5 and 14 defects).

Junctional epidermolysis bullosa: cleavage at the dermo-epidermal junction (lamina lucida). Dystrophic epidermolysis bullosa: subepidermal cleavage (collagen VII).

Course

Depending on variant ranging from mild nuisance to fatal disease. Life long disabling disease, continuous wound care, marked psychosocial problems and reduced quality of life. Epidermolysis bullosa simplex improves with age.

Complications

Variable – none in mild forms; infections, scarring with mutilations and with development of squamous cell carcinomas in more severe variants. Early death possible.

Diagnosis

Clinical findings and laboratory investigations, family history.

Differential diagnosis

Other blistering disorders (pemphigoid, pemphigus, linear IgA bullous dermatosis, epidermolysis bullosa acquisita), peeling skin syndrome, congenital localized absence of skin, suction blisters and mechanical blisters by friction and trauma.

Prevention & Therapy

Intensive skin care, avoidance of pressure and friction. Prevention of secondary infections. No specific systemic therapy available.

Special

Address severe cases to special centers. Autologous skin transplantation and gene therapy. Patient support groups very helpful.

6.1.3 Epidermolysis Bullosa