The molecular features of normal and atopic dermatitis skin in infants, children, adolescents, and adults.

Background: Although atopic dermatitis (AD) often presents in infancy and persists into adulthood, comparative characterization of AD skin among different pediatric age groups is lacking.

Objective: We sought to define skin biopsy profiles of lesional and nonlesional AD across different age groups (0-5-year-old infants with disease duration <6 months, 6-11-year-old children, 12-17-year-old adolescents, ≥18-year-old adults) versus age-appropriate controls.

Methods: We performed gene expression analyses by RNA-sequencing and real-time PCR (RT-PCR) and protein expression analysis using immunohistochemistry.

Can a handheld device accurately measure barrier function in ichthyoses?

Background: Transepidermal water loss (TEWL) is a surrogate measure of skin barrier dysfunction. Historically, devices that measure TEWL are expensive, complex, and require connection to a computer and energy source. Consequently, measurement of skin's TEWL has been limited to the research setting.

Tape strips from early-onset pediatric atopic dermatitis highlight disease abnormalities in nonlesional skin.

Background: Skin biopsies promote our understanding of atopic dermatitis/AD pathomechanisms in infants/toddlers with early-onset AD, but are not feasible in pediatric populations. Tape strips are an emerging, minimally invasive alternative, but global transcriptomic profiling in early pediatric AD is lacking. We aimed to provide global lesional and nonlesional skin profiles of infants/toddlers with recent-onset, moderate-to-severe AD using tape strips.

Loss-of-function variants in C3ORF52 result in localized autosomal recessive hypotrichosis.

Purpose: Localized autosomal recessive hypotrichosis (LAH) has been associated with pathogenic variants in DSG4, encoding a desmosomal protein as well as in LIPH and LPAR6, encoding respectively lipase H, which catalyzes the formation of 2-acyl-lysophosphatidic acid (LPA), and lysophosphatidic acid receptor 6, a receptor for LPA. LPA promotes hair growth and differentiation. In this study we aimed at delineating the genetic basis of LAH in patients without pathogenic variants in these three genes.

Evolution of pathologic T-cell subsets in patients with atopic dermatitis from infancy to adulthood.

Background: The circulating immune phenotype was defined in adults and young children with early atopic dermatitis (AD), but chronologic changes in the blood of infants and children with AD through adolescence have not been explored.

Objective: We sought to compare immune activation and cytokine polarization in the blood of 0- to 5-year-old (n = 39), 6- to 11-year-old (n = 26), 12- to 17-year-old (n = 21) and 18-year-old or older (n = 43) patients with AD versus age-matched control subjects.

Methods: Flow cytometry was used to measure IFN-γ, IL-9, IL-13, IL-17, and IL-22 cytokine levels in CD4/CD8 T cells, with inducible costimulator molecule and HLA-DR defining midterm and long-term T-cell activation, respectively, within skin-homing/cutaneous lymphocyte antigen (CLA) versus systemic/CLA T cells.

Use of Tape Strips to Detect Immune and Barrier Abnormalities in the Skin of Children With Early-Onset Atopic Dermatitis.

Importance: Molecular profiling of skin biopsies is the criterion standard for evaluating the cutaneous atopic dermatitis (AD) phenotype. However, skin biopsies are not always feasible in children. A reproducible minimally invasive approach that can track cutaneous disease in pediatric longitudinal studies or clinical trials is lacking.

The blood proteomic signature of early-onset pediatric atopic dermatitis shows systemic inflammation and is distinct from adult long-standing disease.

Background: Despite increasing evidence that adults with long-standing atopic dermatitis (AD) have systemic inflammation, little is known about systemic inflammation in recent-onset early pediatric AD.

Objective: To analyze blood inflammatory proteins of early pediatric AD.

Methods: Using high-throughput proteomics (proximity extension assay), we assessed 257 inflammatory and cardiovascular risk proteins in the blood of 30 children with moderate to severe AD younger than 5 years of age (within 6 months of onset) compared with age-matched pediatric control individuals and adult patients with AD.