Anatomical patterns of dermatitis in adult filaggrin mutation carriers

Diversity of atopic dermatitis and selection of immune targets

Atopic dermatitis (AD) is a heterogeneous immune-mediated skin disorder affecting people of all ages and ethnicities. Despite the development of targeted therapeutics such as biologics and Janus kinase inhibitors, attaining complete clinical efficacy remains difficult. This therapeutic challenge may be attributed to the complex pathogenesis of AD. Although the TH2 axis has been extensively studied, recent advancements have started to reveal the involvement of additional immune pathways including TH1, TH17, and TH22. Understanding the interplay of these immune axes may contribute to a more personalized therapeutic approach based on patients' molecular profile, with the prospect of improving clinical outcome. This review will discuss studies exploring the molecular profile of AD in both skin and blood across age, ethnicity/race, disease chronicity, IgE levels, filaggrin mutation status, and AD association with other atopic conditions. Moreover, it will explore the potential of personalized treatment strategies based on a patient's distinct immune signature.

Effect of upadacitinib on atopic hand eczema in patients with moderate-to-severe atopic dermatitis: Results from two randomized phase 3 trials

BACKGROUND

Approximately 60% of patients with atopic dermatitis have involvement of the hands adding to the burden of disease.

OBJECTIVE

This analysis aims to evaluate the effect of upadacitinib monotherapy on atopic hand eczema in patients with moderate-to-severe AD over 16 weeks in the Measure Up 1 and 2 studies.

METHODS

Data from patients (ages 12-75) randomized 1:1:1 to receive upadacitinib 15 mg, 30 mg, or placebo once daily in the Measure Up 1 and 2 studies were analysed for impact on atopic hand eczema assessed using the Hand Eczema Severity Index (HECSI). The percent change from baseline in HECSI score was a prespecified additional endpoint at all visits. The proportion of patients with at least a 75% improvement in HECSI score (HECSI 75) was evaluated post hoc.

RESULTS

Patients treated with upadacitinib 15 mg or 30 mg experienced greater improvement in HECSI score compared with placebo as early as Week 1, which was maintained through Week 16. At Week 16, the mean change from baseline in HECSI score for patients receiving upadacitinib 15 mg, 30 mg, and placebo was -68%, -74%, and -15% in Measure Up 1 and -68%, -74% and +21% (positive change indicates worsening for placebo) in Measure Up 2, respectively. A greater proportion of upadacitinib-treated patients achieved HECSI 75 compared with placebo at all timepoints beginning at Week 1 through Week 16.

CONCLUSIONS

Upadacitinib 15 mg and 30 mg monotherapy provided rapid and sustained improvement in atopic hand eczema compared with placebo through Week 16 in patients with moderate-to-severe AD. At Week 16, the observed mean improvements in HECSI score in upadacitinib-treated patients were clinically meaningful based on previous interpretability studies. These results suggest that upadacitinib may be an effective treatment option for atopic hand eczema in patients with moderate-to-severe AD.

A Review of Existing and New Treatments for the Management of Hand Eczema

Hand eczema is a chronic condition that affects an estimated 14.5% of the general population. It has severe quality of life ramifications in those that struggle with it, including days missed from work or school, productivity loss and impaired work functioning. For years, the standard of care included topical moisturizing creams, topical steroids and more recently systemic agents. As new therapeutic targets emerge and recent advances are being developed, it is now more possible than ever that hand eczema can be managed via the underlying mechanisms. A review of the literature was conducted to identify current treatment options for hand eczema and chronic hand eczema. The terms 'hand eczema', 'hand dermatitis' were used to search PubMed, CENTRAL and Embase. To identify new therapies still undergoing investigation, we used the terms 'hand eczema', 'hand dermatitis', 'atopic dermatitis', and 'vesicular eczema of hands and/or feet' to search Clinicaltrials.gov for all studies until December 2022. There were 56 ongoing clinical trials identified for pharmacological treatments for hand eczema on Clinicaltrials.gov from 2000 - 2022, with 16 that are new or ongoing. These included studies for dupilumab, ruxolitinib, delgocitinib (LEO124249), gusacitinib (ASN002), AFX 5931, and roflumilast (ARQ-252). Two major classes of drugs emerging for the treatment of hand eczema include IL-4/IL-13 inhibitors and JAK inhibitors. With the increase in efficacy seen with these new drugs, we are also noting improved adverse effect profiles, making them attractive options to add to a clinician's management toolbox for patients with hand eczema.

Biomarkers associated with the development of comorbidities in patients with atopic dermatitis: A systematic review

Biomarkers associated with the development of comorbidities in atopic dermatitis (AD) patients have been reported, but have not yet been systematically reviewed. Seven electronic databases were searched, from database inception to September 2021. English language randomized controlled trials, prospective and retrospective cohort, and case-control studies that investigated the association between a biomarker and the development of comorbidities in AD patients were included. Two authors independently screened the records for eligibility, one extracted all data, and critically appraised the quality of studies and risk of bias. Fifty six articles met the inclusion criteria, evaluating 146 candidate biomarkers. The most frequently reported biomarkers were filaggrin mutations and allergen specific-IgE. Promising biomarkers include specific-IgE and/or skin prick tests predicting the development of asthma, and genetic polymorphisms predicting the occurrence of eczema herpeticum. The identified studies and biomarkers were highly heterogeneous, and associated with predominately moderate-to-high risk of bias across multiple domains. Overall, findings were inconsistent. High-quality studies assessing biomarkers associated with the development of comorbidities in people with AD are lacking. Harmonized datasets and independent validation studies are urgently needed.

Classifying atopic dermatitis: a systematic review of phenotypes and associated characteristics

Atopic dermatitis is a heterogeneous disease, accompanied by a wide variation in disease presentation and the potential to identify many phenotypes that may be relevant for prognosis and treatment. We aimed to systematically review previously reported phenotypes of atopic dermatitis and any characteristics associated with them. Ovid EMBASE, Ovid MEDLINE and Web of Science were searched from inception till the 12th of February 2021 for studies attempting to classify atopic dermatitis. Primary outcomes are atopic dermatitis phenotypes and characteristics associated with them in subsequent analyses. A secondary outcome is the methodological approach used to derive them. In total, 8,511 records were found. By focusing only on certain clinical phenotypes, 186 studies were eligible for inclusion. The majority of studies were hospital-based (59%, 109/186) and cross-sectional (76%, 141/186). The number of included patients ranged from seven to 526,808. Data-driven approaches to identify phenotypes were only used in a minority of studies (7%, 13/186). Ninety-one studies (49%) investigated a phenotype based on disease severity. A phenotype based on disease trajectory, morphology and eczema herpeticum was investigated in 56 (30%), 22 (12%) and 11 (6%) studies, respectively. Thirty-six studies (19%) investigated morphological characteristics in other phenotypes. Investigated associated characteristics differed between studies. In conclusion, we present an overview of phenotype definitions used in literature for severity, trajectory, morphology and eczema herpeticum, including associated characteristics. There is a lack of uniform and consistent use of atopic dermatitis phenotypes across studies.

Vesicular hand eczema transcriptome analysis provides insights into its pathophysiology

Hand eczema is a common inflammatory skin condition of the hands whose pathogenesis is largely unknown. More insight and knowledge of the disease on a more fundamental level might lead to a better understanding of the biological processes involved, which could provide possible new treatment strategies. We aimed to profile the transcriptome of lesional palmar epidermal skin of patients suffering from vesicular hand eczema using RNA‐sequencing. RNA‐sequencing was performed to identify differentially expressed genes in lesional vs. non‐lesional palmar epidermal skin from a group of patients with vesicular hand eczema compared to healthy controls. Comprehensive real‐time quantitative PCR analyses and immunohistochemistry were used for validation of candidate genes and protein profiles for vesicular hand eczema. Overall, a significant and high expression of genes/proteins involved in keratinocyte host defense and inflammation was found in lesional skin. Furthermore, we detected several molecules, both up or downregulated in lesional skin, which are involved in epidermal differentiation. Immune signalling genes were found to be upregulated in lesional skin, albeit with relatively low expression levels. Non‐lesional patient skin showed no significant differences compared to healthy control skin. Lesional vesicular hand eczema skin shows a distinct expression profile compared to non‐lesional skin and healthy control skin. Notably, the overall results indicate a large overlap between vesicular hand eczema and earlier reported atopic dermatitis lesional transcriptome profiles, which suggests that treatments for atopic dermatitis could also be effective in (vesicular) hand eczema.

Hand eczema among Dutch beekeepers - a cross-sectional study

BACKGROUND AND OBJECTIVES

Studies of beekeepers have mostly focused on contact allergy to propolis. The overall prevalence of hand eczema (HE) in beekeepers has not been studied. Our objectives were to gain insight into the prevalence of HE in the Dutch beekeeper population; to define the impact of beekeeping activities on HE and vice versa; and to determine associated factors.

PATIENTS AND METHODS

We used a cross-sectional online survey. Dutch beekeepers answered questions on beekeeping activities, the prevalence and characteristics of HE, including severity, and the impact of the disease on beekeeping.

RESULTS

We analyzed 833 surveys (12 % of Dutch beekeepers). The one-year prevalence of HE was 13.2 %, and the lifetime prevalence was 20.5 %. In 28 patch-tested beekeepers with hand eczema, eight (28.6 %) were allergic to propolis. Atopic dermatitis was the only variable associated with HE: the odds ratio was 4.53 (95 % confidence interval 2.78-7.38). One in three beekeepers reported that HE was caused or worsened by beekeeping, although only 3.8 % reported working less at beekeeping because of HE, and the impact of HE on beekeeping activities (as perceived by beekeepers) is low.

CONCLUSIONS

In this sample of Dutch beekeepers, hand eczema was more prevalent than in the general population, but seems to have had little impact on the beekeeping activities of the majority of beekeepers.

Atopic Dermatitis in Adults

Atopic dermatitis (AD) was once thought to be a benign childhood disease that remitted with increasing age. However, recent studies have transformed the understanding of AD, particularly in adult patients. AD is common in adults and can lead to substantial disability by negatively affecting sleep, mental health, and quality of life. There seem to be different genetic, immunologic, and epidemiologic risk factors for AD in adults than in children. This article examines the pathophysiology, epidemiology, heterogeneous clinical presentation, burden, diagnosis, and treatment of adult AD.

The role of filaggrin in atopic dermatitis and allergic disease

OBJECTIVE

To provide an overview of filaggrin biology and the role of filaggrin variants in atopic dermatitis (AD) and allergic disease.

DATA SOURCES

We performed a PubMed literature review consisting mainly of studies relating to filaggrin in the last 5 years.

STUDY SELECTIONS

We selected articles that were found in PubMed using the search terms filaggrin, atopic dermatitis, skin barrier, and atopy.

RESULTS

Filaggrin plays an important role in the development of AD and allergic disease. Novel methods in measuring filaggrin expression and identifying filaggrin mutations aid in stratifying this patient cohort. We review new insights into understanding the role of filaggrin in AD and allergic disease.

CONCLUSION

Filaggrin remains a very important player in the pathogenesis of atopic dermatitis and allergic disease. This review looks at recent studies that aid our understanding of this crucial epidermal protein.

Epidemiology of adult atopic dermatitis

Atopic dermatitis (AD) is driven by a complex gene-environment interaction. Many of the risk factors and genetic underpinning previously observed for pediatric AD may not apply to adult atopic dermatitis, suggesting that these may largely be different disorders. Whereas AD is classically thought of as a pediatric disease, recent studies have shown high rates of disease in adults as well. Risk factors for persistence of childhood-onset AD, as well as adult-onset AD, are reviewed. Adults with AD are particularly vulnerable to exogenous insults from the outside environment, including climate, ultraviolet exposure, pollution, irritants and pruritogens, and microbes. Finally, adult AD is associated with a substantial health care burden, with increased utilization, direct and indirect costs of care, and lost work productivity.

Factors associated with combined hand and foot eczema

BACKGROUND

As for hand eczema, the aetiology of foot eczema is multifactorial and not very well understood. The aim of the present study was to identify factors associated with foot eczema in a cohort of hand eczema patients being classified into different subgroups.

METHODS

Associations between foot and hand eczema were studied in a cross-sectional design in a cohort of hand eczema patients. Consecutive patients were recruited from nine different European Centres during the period October 2011-September 2012. Data on demographic factors, presence of foot eczema, hand eczema duration and severity, and whether the hand eczema was work-related or not were available, as well as patch-test results.

RESULTS

Of a total of 427 hand eczema patients identified, information on foot eczema was available in 419 patients who were included in the present study. A total of 125 patients (29.8%) had concomitant foot and hand eczema. It was found more often in association with hyperkeratotic hand eczema (P = 0.007) and was less often associated with irritant hand eczema (P < 0.001). However, foot eczema was nevertheless found in 18% of patient with irritant hand eczema and in 25% of patients with occupational hand eczema. Combined foot and hand eczema was associated with more severe and long-standing hand eczema (P < 0.001 and P = 0.004, respectively). Contact allergy was found in 51.8% with no difference between patients with combined foot and hand eczema and patients with hand eczema only.

CONCLUSION

Occurrence of combined foot and hand eczema is a common finding and not restricted to endogenous hand eczema.

Twin Studies of Atopic Dermatitis: Interpretations and Applications in the Filaggrin Era

Aim. The aim of this study was to conduct a systematic review of population-based twin studies of (a) the concordance and heritability of AD and (b) the relationship between AD and asthma and, furthermore, to reinterpret findings from previous twin studies in the light of the emerging knowledge about filaggrin and its role in the atopic march and provide suggestions for future research in this area. Methods. We identified all twin studies (published after 1970) that have calculated the concordance rate and/or the heritability of AD, or the genetic and environmental correlations between AD and asthma. Results. Reported concordance rates for AD ranged, respectively. From 0.15 to 0.86 for MZ and from 0.05 to 0.41 for DZ twins, with an overall ratio of MZ : DZ twins of approximately three. The heritability of AD was estimated to be approximately 75%, and the association between AD and asthma was around 85% explained by genetic pleiotropy. Conclusions. Genetic factors account for most of the variability in AD susceptibility and for the association between AD and asthma. Controversy remains as to whether the atopic diseases are causally related or whether they are diverse clinical manifestations of a common, underlying (genetic) disease trait. Future twin studies may help solve this enigma.