['The ichthyoses are rare genetic disorders associated with generalized scaling, erythema, and epidermal barrier impairment. Pathogenesis-based therapy is largely lacking because the underlying molecular basis is poorly understood.', 'We sought to characterize molecularly cutaneous inflammation and its correlation with clinical and barrier characteristics.', 'We analyzed biopsy specimens from 21 genotyped patients with ichthyosis (congenital ichthyosiform erythroderma, n\xa0=\xa06; lamellar ichthyosis, n\xa0=\xa07; epidermolytic ichthyosis, n\xa0=\xa05; and Netherton syndrome, n\xa0=\xa03) using immunohistochemistry and RT-PCR and compared them with specimens from healthy control subjects, patients with atopic dermatitis (AD), and patients with psoriasis. Clinical measures included the Ichthyosis Area Severity Index (IASI), which integrates erythema (IASI-E) and scaling (IASI-S); transepidermal water loss; and pruritus.', 'Ichthyosis samples showed increased epidermal hyperplasia (increased thickness and keratin 16 expression) and T-cell and dendritic cell infiltrates. Increases of general inflammatory (IL-2), innate (IL-1β), and some T'] Is an IL-17-dominant immune profile shared across the major orphan forms of ichthyosis?