Introduction
Netherton syndrome (NS) is a rare autosomal recessive genodermatosis (OMIM #256500) characterized by superficial scaling, atopic manifestations, and multisystemic complications, a triad of congenital ichthyosiform erythroderma or ichthyosis linearis circumflexa, hair shaft abnormalities, and immune dysregulation. Its incidence is one in 200 000 newborns. It may represent up to 18% of infants with congenital erythroderma.1 NS is caused by loss-of-function mutations in Serine Protease Inhibitor Kazal type 5 (SPINK5) gene, which is located on chromosome 5q31-32 and encodes Lympho-Epithelial Kazal-type-related protease inhibitor (LEKTI).2 To date, a total of 108 variants have been found, encompassing all types of mutations.3 LEKTI, expressed in the thymus and epithelia, is a direct inhibitor of kallikrein-related peptidases and cathepsin G and affects epidermal desquamation and altered skin barrier function. Skin manifestations in NS include ichthyosiform erythroderma (IE) or ichthyosis linearis circumflexa (ILC), a specific hair shaft defect called trichorrhexis invaginata (bamboo hair), and an atopic diathesis. Indeed, NS is a multisystemic disease with characteristic cutaneous and numerous extracutaneous manifestations.4Diagnosis of NS can be enhanced with histologic examination;5 immunostaining shows the absence or reduction of LEKTI expression in the granular layer of the epidermis and in the hair follicles.6 Abnormalities of the hair shaft could be detected in only 20-50% of affected hairs.7 Laboratory findings show peripheral eosinophilia and elevated IgE levels. It is very difficult to distinguish atypical NS from other types of ichthyosis; detection of gene mutations in SPINK5 is crucial for diagnosis. Current therapy for patients with NS is mainly supportive, as there is no curative or specific treatment, especially for children with NS, but targeted therapies are being developed.
We describe a child with genetically proven Netherton syndrome, for whom intravenous immunoglobulin for 5 months proven beneficial.