Clinical characteristics of Korean patients with filaggrin-related atopic dermatitis

Filaggrin gene polymorphisms in Indian children with atopic dermatitis: A cross-sectional multicentre study

Background Filaggrin (FLG) gene encoding the protein filaggrin plays an important role in barrier function of the skin and its alteration is a predisposing factor for atopic dermatitis. FLG gene variants result in absent or decreased filaggrin protein. Worldwide, the prevalence of FLG variants ranges from 14 to 56%. FLG null variants are distinct in each population. Objectives To study the FLG gene polymorphisms in Indian children and attempt a genotype-phenotype correlation in atopic dermatitis. Methods This was a cross-sectional, multicentre study conducted on 75 Indian children. Demographic details, clinical features and identified FLG null variants were recorded. We performed a whole gene sequencing of the entire FLG coding region using next-generation sequencing technology. Results The prevalence of FLG null variants was 34.7%. A total of 20 different FLG loss of function variants in 26 children were documented. Sixteen (80%) variants were novel and four (20%) were previously reported in Asian and European populations. We found a statistically significant association between FLG variants with early age of onset of atopic dermatitis (P = 0.016) and elevated serum IgE levels (P = 0.051). There was no significant difference between atopic dermatitis phenotypes in children having one variant as compared to children harbouring two or more null variants. Limitation Small sample size. Conclusion Our study reports a unique set of FLG variants different from Asian and European populations, with these variants being significantly associated with an early age of onset of atopic dermatitis and elevated serum IgE levels.

Filaggrin mutations in relation to skin barrier and atopic dermatitis in early infancy

BACKGROUND

Loss-of-function mutations in the skin barrier gene filaggrin (FLG) increase the risk of atopic dermatitis (AD), but their role in skin barrier function, dry skin and eczema in infancy is unclear.

OBJECTIVES

To determine the role of FLG mutations for impaired skin barrier function, dry skin, eczema and AD at three months of age and through infancy.

METHODS

FLG mutations were analyzed in 1836 infants in the Scandinavian population-based PreventADALL study. Transepidermal water loss (TEWL), dry skin, eczema and AD were assessed at three, six and 12 months of age.

RESULTS

Filaggrin mutations were observed in 166 (9%) infants. At three months, carrying FLG mutations was not associated with impaired skin barrier function (TEWL > 11.3 g/m² /h) or dry skin, but with eczema (OR(95%CI): 2.76 (1.81, 4.23), p < 0.001). At six months, mutation carriers had significantly higher TEWL than non-mutation carriers (mean (95%CI) 9.68 (8.69, 10.68) vs. 8.24 (7.97, 8.15), p < 0.01) and at three and six months an increased risk of dry skin on truncus (OR: 1.87 (1.25, 2.80), p = 0.002; 2.44 (1.51, 3.95), p < 0.001) or extensor limb surfaces (1.52 (1.04, 2.22), p = 0.028; 1.74 (1.17, 2.57), p = 0.005). FLG mutations were associated with eczema and AD in infancy.

CONCLUSION

Filaggrin mutations were not associated with impaired skin barrier function or dry skin in general at three months of age, but increased the risk for eczema, as well as for dry skin on truncus and extensors at three and six months.

Genetics and Epigenetics of Atopic Dermatitis: An Updated Systematic Review

BACKGROUND

Atopic dermatitis is a common inflammatory skin disorder that affects up to 15-20% of the population and is characterized by recurrent eczematous lesions with intense itching. As a heterogeneous disease, multiple factors have been suggested to explain the nature of atopic dermatitis (AD), and its high prevalence makes it necessary to periodically compile and update the new information available. In this systematic review, the focus is set at the genetic and epigenetic studies carried out in the last years.

METHODS

A systematic literature review was conducted in three scientific publication databases (PubMed, Cochrane Library, and Scopus). The search was restricted to publications indexed from July 2016 to December 2019, and keywords related to atopic dermatitis genetics and epigenetics were used.

RESULTS

A total of 73 original papers met the inclusion criteria established, including 9 epigenetic studies. A total of 62 genes and 5 intergenic regions were described as associated with AD.

CONCLUSION

Filaggrin (FLG) polymorphisms are confirmed as key genetic determinants for AD development, but also epigenetic regulation and other genes with functions mainly related to the immune system and extracellular matrix, reinforcing the notion of skin homeostasis breakage in AD.

Adult-Onset Atopic Dermatitis: Presentations and Progress

Atopic dermatitis (AD) is a chronic skin disease characterized by barrier dysfunction and immune dysregulation that affects approximately 20% of children and 2-5% of adults worldwide. Traditionally, AD has been considered a disease of childhood with many cases resolving before adulthood. However, in recent years, the prevalence of adult AD is increasingly recognized to be substantial, but it is uncertain whether this increase is due to increased childhood-persistent or relapsed AD, or new adult-onset AD. This highlights a need for further investigation into the adult AD population and evaluation of phenotypes in the adult-onset cohort. In this literature review, we examine five studies focused on adult-onset AD phenotype, conducted between 2013 and 2017. The most commonly reported body regions affected in adult-onset AD were the hands, eyelids, neck, and flexural surfaces of the upper limbs. These vary from childhood-onset AD findings, which are less specific to body regions other than flexural areas. These findings have implications for diagnostic accuracy and treatment of AD, including considerations for therapeutic choices and inclusion and exclusion criteria in clinical trials.

Approach to the Assessment and Management of Pediatric Patients With Atopic Dermatitis: A Consensus Document. Section I: Overview of Pediatric Atopic Dermatitis

Pediatric atopic dermatitis (AD) is one of the most common dermatoses encountered by health-care providers treating children. Diagnosis of AD is clinical, with no universally accepted biomarkers or assessment tools. Patient-reported outcomes and subjective assessments of quality of life in both the patient and family are important considerations when treating pediatric AD. Here, we provide an overview of pediatric AD epidemiology, its clinical presentation, burden, diagnosis, and assessment, with a focus on implications for patient counseling in order to optimize care.