Epidermolysis bullosa junctionalis, generalized severe (historical: Herlitz type)Q81.1

Hereditary, infantile, lethal, blistering dermatosis with cleft formation along the basement membrane. Most severe form of congenital junctional epidermolysis. No oesophageal involvement.

Incidence at 0.5/100,000 per year

Autosomal recessive inheritance. Mutation in the genes for laminin-5(LAMA3, LAMB3, LAMC2) mapped on chromosomes 1q25/1q31. Absence of the protein in the skin results in extreme skin fragility.

Integument: Large, flaccid blisters of varying size with serous or hemorrhagic contents throughout the integument.

There is an increased risk of malignant development of the skin (squamous cell carcinoma of the skin, rarely formation of malignant melanoma).

Blistering is followed by poorly healing erosions and granulation tissue, especially on the acras. Formation of strictures.

Furthermore:

• Blister formation on the oral mucosa (50-75%).
• Onychoatrophy or onychodystrophy (75-100%) due to subungual blistering.
• Involvement of the eyes (blisters, scarring ectropia, corneal or conjunctival erosions) is found in more than 50% of patients.
• Involvement of larynx, trachea/ bronchi (25-50%): this results in permanent hoarseness, stridor
• pharynx (25-50%) eating difficulties
• Hypoplasia of enamel or tooth growth with increased susceptibility to caries (75-100%).
• Anemia (75-100%)
• Pseudosyndactyly (1-10%)

Subepidermal blistering: Bullous detached epidermis with well preserved basal cell row in the blister roof. Clear lymphohistiocytic infiltrates in the upper corium.

Electron microscopy: junktiolytic blistering, reduction in number or appearance of morphologically altered hemidesmosomes.

Decreased fluorescence of laminin-5 at the bladder roof.

Avoidance of mechanical trauma, positioning on special air or water padded beds, soft clothing, wearing clothes from the left side if necessary to avoid chafing effects at the seams.

Careful personal hygiene with disinfecting baths and sterile covering of blisters and erosions.

Symptomatic (see below epidermolysis bullosa group). Dressing with hydrogels (e.g. Intrasite) or hydrocolloid foils (e.g. Varihesive E).

Experimental: Transplantation of autologous transgenic keratinocyte cultures. Contact:Bergmannsheil/Bochum (Hirsch T et al. 2017)

• Glucocorticoids such as prednisolone, medium to high doses 60-120 mg/day (e.g. Decortin H), later minimal maintenance therapy can be life-saving. In case of superinfection or even sepsis, antibiotics should be administered in time.
• Experimental:
• In a study in 6 children with EB a significant improvement of symptoms was achieved by stem cell transplantation. Long-term results of this high-risk therapeutic approach are not yet available.

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