A Case of Annular Epidermolytic Ichthyosis Resulting from a de Novo Mutation, p.I479T, in Keratin 1 Gene

Abstract

We report a case of annular epidermolytic ichthyosis (AEI) resulting from de novo keratin 1 gene mutation. AEI is a rare autosomal dominantly inherited cornification disorder and is a distinct phenotypic variant of bullous congenital ichthyosiform erythroderma. Blisters and erosions in AEI are widespread; hence, initially, it is sometimes mistaken with epidermolysis bullosa, acrodermatitis enteropathica, and staphylococcal scalded skin syndrome. Genetic tests including next-generation sequencing and Sanger sequencing are essential for AEI diagnosis. AEI is treated symptomatically by wound dressing, prevention of infection, and the use of emollients, humectants, and keratolytic products; topical or systemic retinoids may also prove helpful.

Keywords: Annular epidermolytic ichthyosis; keratin 1; mutation; next-generation sequencing.

Figure 1

(a and b) Blisters, erosions, and peeling with erythema on the thighs; (c and d) intraepidermal vesicle and vacuolar degeneration of keratinocytes in superficial layer of epidermis (hematoxylin–eosin staining, original magnification c×100, d×400); (e) the arrow indicates the heterozygous mutation (the reverse strand A→G is shown in the upper panel) in the patient; this mutation predicts the amino acid substitution 1436T→C, in the KRT 1 gene, compared with her old brother's (lower panel)