Epidermólise Bolhosa em animais.

Abstract

This thesis includes three papers on epidermolysis bullosa (EB) in animals, which is an hereditary disease, characterized by the formation of blisters and erosions on the skin and mucous in response to minor mechanical trauma. The first paper reviews the diagnosis, classification, epidemiology, mode of inheritance, clinical, pathology, and ultrastructural and molecular changes of EB reported in animals. Based on the ultrastructural level of tissue separations EB is divided into three types: simplex, junctional, and dystrophic. In humans it is estimated that EB affect 1 in 17000 live births, but in animal the frequency of EB is not estimated. The clinical and pathological findings are similar in all types of EB, varying only in intensity. EB is due to mutations in genes that express the protein constituent the cytoskeleton of the basal keratinocytes or of the basement membrane zone (BMZ). In the second paper, clinical, histopathological, and ultrastructural findings of dystrophic EB in goats transmitted by an autosomal recessive gene are reported. The goats presented with exungulation, erosions, crusts and scars on the skin and ulcers in the oral cavity. Histologically, the skin showed subepidermal separation, with clefts filled with clear eosinophilic fluid, cellular debris or neutrophils. Ultrastructurally, the site of blister formation was the sub-lamina densa in the BMZ. In skin with blister formation and in clinically uninvolved skin, the basal lamina was preserved, but the anchoring fibrils were scarce and rudimentary. It is suggested that the disease is similar to human severe generalized recessive dystrophic EB. In the third paper, a case of EB in a calf is reported. It was presented exungulation of all hooves, widespread erosions and crusts on the skin, and ulcers in the oral cavity. Histologically, the skin showed subepidermal clefts. Ultrastructurally, there was epidermal-dermal separation at the level of the lamina lucida, with the lamina densa attached to the papillary dermis. The hemidesmosomes were poorly defined and small. The clinical, histological and ultrastructural findings are characteristic of junctional EB.