Epidermolytic ichthyosis in a dog: clinical, histopathological, immunohistochemical and ultrastructural findings.

Epidermolytic hyperkeratosis (EH) in man is a complex of congenital, ichthyosiform skin diseases characterized clinically by blistering and hyperkeratosis. These clinical signs are the result of a collapse of the cytoskeleton, seen ultrastructurally as tonofilament clumping and cytolysis within terminally differentiating epidermal cells. In man, specific mutations in keratin 1, 2e, 9 or 10 underlie the various types of EH. This report describes the clinical, histopathological, immunohistochemical and ultrastructural findings in a 6-month-old dog with severe multifocal hyperkeratosis. The morphological changes were comparable with those of EH in man, indicating that this disease, presumably with a similar underlying pathogenetic mechanism, also occurs in the dog. Copyright 2000 Harcourt Publishers Ltd.