INTRODUCTION
Lichenification, associated with disease chronicity in moderate to severe atopic dermatitis (AD), is a skin sign characterized by skin thickening with demarcated skin lines and leathery aspect, partially resulting from repetitive scratching and rubbing due to pruritus.1-3 AD lichenification can occur at any age and is more prevalent in patients from South-Eastern Asian or African racial backgrounds.3,4
Chronic lichenified AD lesions are histologically characterized by epidermal hyperplasia with acanthosis and elongation of the rete ridges, hyperkeratosis, and minimal spongiosis, with an increase in epidermal IgE-bearing dendritic cells.5 The dermal mononuclear cell infiltrate is dominated by macrophages and mast cells, usually fully granulated. There may be some increase in collagen, manifesting as fibrosis in the upper dermis, including the papillae.5,6
Type 2 inflammation induces epidermal hyperplasia with acanthosis directly through overexpression of interleukin (IL)-4 and IL-13.7 Dupilumab, a fully human monoclonal antibody, specifically binds to a single target, the IL-4 receptor alpha (IL-4Rα), and inhibits signaling of both IL-4 and IL-13. Dupilumab has been shown to modulate markers of epidermal hyperplasia and keratinocyte proliferation in clinical trials8,9 and real-world studies.10
Chronic lichenified AD lesions are histologically characterized by epidermal hyperplasia with acanthosis and elongation of the rete ridges, hyperkeratosis, and minimal spongiosis, with an increase in epidermal IgE-bearing dendritic cells.5 The dermal mononuclear cell infiltrate is dominated by macrophages and mast cells, usually fully granulated. There may be some increase in collagen, manifesting as fibrosis in the upper dermis, including the papillae.5,6
Type 2 inflammation induces epidermal hyperplasia with acanthosis directly through overexpression of interleukin (IL)-4 and IL-13.7 Dupilumab, a fully human monoclonal antibody, specifically binds to a single target, the IL-4 receptor alpha (IL-4Rα), and inhibits signaling of both IL-4 and IL-13. Dupilumab has been shown to modulate markers of epidermal hyperplasia and keratinocyte proliferation in clinical trials8,9 and real-world studies.10
MATERIALS AND METHODS
Study Design
This post hoc analysis included pooled data from 5 double-blind, placebo-controlled studies of dupilumab conducted in patients aged 6 years and older with moderate and severe AD. Detailed methodology and primary results (including safety) have been reported.11-14 LIBERTY AD PEDS (NCT03345914) included children (aged 6-11 years) with severe AD, randomized to placebo or
This post hoc analysis included pooled data from 5 double-blind, placebo-controlled studies of dupilumab conducted in patients aged 6 years and older with moderate and severe AD. Detailed methodology and primary results (including safety) have been reported.11-14 LIBERTY AD PEDS (NCT03345914) included children (aged 6-11 years) with severe AD, randomized to placebo or
