Introduction
Bullous epidermolysis(epidermolysis bullosa, EB) is divided into hereditary and acquired. Hereditary EB includes at least 23 different types, which can be divided into three categories according to the location of the disease: 1 simple bullous epidermolysis (simplexEB, EBS), blisters in the epidermis 2 borderline bullous epidermolysis (junctionalEB, JEB), blisters occur in the transparent layer; 3 dystrophic dystrophic EB (DEB), blister occurs in the dense lower layer.
Pathogenesis
[Etiology and pathogenesis]
EBS has been shown to be involved in gene mutations encoding keratin 5 and 14; JEB is associated with gene mutations encoding substances such as laminin 5, type VII collagen; DEB is associated with gene mutations encoding type VII collagen. Due to mutations in the genes encoding the structural components of the epidermis and the basement membrane, these proteins are structurally or structurally abnormal, resulting in the production of blisters at different anatomical sites.
Clinical manifestation
A common feature of various types of bullous epidermolysis is the appearance of blisters and blood blisters after a slight friction or collision (Figure 25-4). Occurs in the extremities and the extremities of the limbs. In severe cases, it can involve any part. After the leather bed is combined, a scar or a millet rash can be formed, and the skin lesions with repeated attacks on the extremities can cause the nails to fall off.
The simple type only affects the extremities and the extremities of the extremities, does not involve the mucosa, and the lesions are the most superficial, and generally no scars are left after the healing. Malnourished type can affect any part (including mucosa), the condition is more serious, often after birth, skin lesions appear, and the position is deep, leaving obvious scars after healing, repeated blisters and scars on the extremities can make the fingers Between the skin adhesions, the phalanx atrophy forms a claw-shaped hand; the oropharynx mucosa repeatedly collapses, crusting can cause mouth opening, difficulty swallowing, and poor after treatment. Border type is rare, widespread blisters, bullae and erosion surface appear after birth The prognosis is poor, and most of them die within 2 years old.
[Histological pathology and immunopathology] Transmission electron microscopy and immunohistochemistry showed that the blister of EBS was located in the epidermis, the blister of DEB was located in the dense lower layer, and the blister of JEB was located in the transparent layer.
[Diagnosis and differential diagnosis] According to family history, clinical features, combined with immunohistochemistry and transmission electron microscopy can generally confirm the diagnosis and classification.
It should be differentiated from acquired bullous epidermolysis. The clinical manifestations of the latter are similar to those of hereditary bullous epidermolysis. There may be anti-basement membrane autoantibodies in serum. In addition, it should be differentiated from bullous pemphigoid and pemphigus.
treatment
There is currently no specific treatment. The skin should be protected from friction and compression. Non-adhesive synthetic dressings, sterile gauze or broad-spectrum antibiotic ointments can be used to prevent infection, and supportive therapy should be strengthened.
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