Clinical and Genetic Features of the Lamellar Ichthyoses: Evidence for Three Different Types

Abstract

The congenital ichthyoses comprise a variety of different keratinization defects [1, 5, 9]. As the biochemical basis of the various types of congenital ichthyosis is still unknown, a correct diagnosis depends on careful examination of the clinical features and on further information provided by histology, electron microscopy, and pedigree analysis. The congenital ichthyoses may be classified into those forms in which ichthyosis is associated with other symptoms and thus present as part of a syndrome (syndromic congenital ichthyoses) (Table 1) and into those types without associated signs (nonsyndromic congenital ichthyoses). In this latter group it is possible to distinguish between lamellar ichthyosis and bullous ichthyosiform erythroderma (BIE). BIE ist inherited as an autosomal dominant trait and exhibits specific histological changes that are referred to as “granular degeneration” [5] or epidermolytic hyper-keratosis [2]. Different nomenclature retained for historical reasons has contributed to a certain confusion in the classification of the congenital ichthyoses. Nowadays the designations nonbullous congenital ichthyosiform erythroderma, ichthyosis congenita mitis, and lamellar ichthyosis are used synonymously [1, 4, 5].