Skin and systemic inflammation in adults with atopic dermatitis before and after whole-body topical betamethasone 17-valerate 0.1% or tacrolimus 0.1% treatment: A randomized controlled study.

BACKGROUND: Atopic dermatitis (AD) is mainly driven by type 2 inflammation and often treated with topical agents. Studies comparing differences in biomarkers between these treatments are lacking. OBJECTIVES: The aim of this study was to evaluate the effects of topical betamethasone 17-valerate 0.1% and tacrolimus 0.1% ointment on skin barrier function and inflammatory biomarkers in skin and blood in adults with AD. METHODS: In this randomized parallel-group double-blind double-dummy active-comparator study design, 36 adults with AD were treated with either whole-body topical corticosteroid (betamethasone ointment 0.1% plus placebo once daily, n = 18) or calcineurin inhibitor (tacrolimus ointment 0.1% twice daily, n = 18). At baseline, after 2 weeks of daily treatment and after further 4 weeks of twice-weekly maintenance treatment, we evaluated AD severity, levels of natural moisturizing factor (NMF) and cytokines in the skin and blood and characterized circulating T cells. RESULTS: Mean AD severity at baseline corresponded to moderate disease and decreased significantly in both groups. Levels of NMF increased significantly in the tacrolimus group after 2 weeks of treatment (p = 0.002) and tended to increase more than betamethasone at week 6 (p = 0.06). Most skin cytokines decreased with both treatments. However, IL-8, IL-18, IL-22, IP-10, MDC, MMP-9 and TARC were significantly more decreased with betamethasone than tacrolimus after 2 weeks, while after 6 weeks this was only the case for IL-8 and MMP-9. Approximate half of the systemic cytokines decreased significantly with both treatments, but betamethasone decreased MDC significantly more after 2 weeks of treatment. T-cell characterization analyses indicated slight differences in the expression and activation of T cells between groups. CONCLUSION: Topical treatment of AD with betamethasone and tacrolimus ointment effectively reduced disease severity, cutaneous and systemic inflammatory markers. Betamethasone was more effective in decreasing inflammation, but tacrolimus improved skin hydration (NMF levels) more than betamethasone.

Natural moisturising factor constituents in South African nursing students.

BACKGROUND: The majority of South African healthcare workers are Black Africans with dark-pigmented skin. Studies on how the markers of skin barrier function and natural moisturising factor (NMF) compare between dark and light-pigmented skin are limited. Quantifying NMF in a nursing student population during their practical training at university may provide valuable insight into their potential susceptibility to skin conditions associated with low NMF. OBJECTIVES: The objectives of this study were to quantify and compare NMF content of Black African, Mixed Race and White nursing students from their dominant dorsal hand. METHODS: Forty-nine White, 32 Black African and 5 Mixed Race nursing students participated in this study. Tape strip samples were collected from the participants' dominant dorsal hand and NMF content was measured, including histidine (HIS), pyrrolidone carboxylic acid (PCA), trans-urocanic acid (t-UCA) and cis-urocanic acid (c-UCA), as well as cytokines interleukin-1 alpha (IL-1α) and interleukin-1 receptor antagonist (IL-1RA). RESULTS: No statistically significant differences in PCA, t-UCA, c-UCA, IL-1α or IL-1RA were found between Black African and White nursing students. HIS was significantly (p = 0.001) higher in White nursing students when compared to Black African students. The ratio of tot-UCA/HIS was significantly higher in Black Africans (p = 0.0002) when compared to White nursing students. CONCLUSION: No significant differences were established in NMF content between White and Black African nursing students, other than HIS which was significantly higher in White students than in Black African students. Different HIS levels between the racial groups suggest variation in histidase activity which may be related to skin pH and pigmentation. This finding may suggest that nursing students at the beginning of their careers may have similar susceptibility to skin diseases related to NMF.

Staphylococcus aureus binds to the N-terminal region of corneodesmosin to adhere to the stratum corneum in atopic dermatitis.

Staphylococcus aureus colonizes the skin of the majority of patients with atopic dermatitis (AD), and its presence increases disease severity. Adhesion of S. aureus to corneocytes in the stratum corneum is a key initial event in colonization, but the bacterial and host factors contributing to this process have not been defined. Here, we show that S. aureus interacts with the host protein corneodesmosin. Corneodesmosin is aberrantly displayed on the tips of villus-like projections that occur on the surface of AD corneocytes as a result of low levels of skin humectants known as natural moisturizing factor (NMF). An S. aureus mutant deficient in fibronectin binding protein B (FnBPB) and clumping factor B (ClfB) did not bind to corneodesmosin in vitro. Using surface plasmon resonance, we found that FnBPB and ClfB proteins bound with similar affinities. The S. aureus binding site was localized to the N-terminal glycine-serine-rich region of corneodesmosin. Atomic force microscopy showed that the N-terminal region was present on corneocytes containing low levels of NMF and that blocking it with an antibody inhibited binding of individual S. aureus cells to corneocytes. Finally, we found that S. aureus mutants deficient in FnBPB or ClfB have a reduced ability to adhere to low-NMF corneocytes from patients. In summary, we show that FnBPB and ClfB interact with the accessible N-terminal region of corneodesmosin on AD corneocytes, allowing S. aureus to take advantage of the aberrant display of corneodesmosin that accompanies low NMF in AD. This interaction facilitates the characteristic strong binding of S. aureus to AD corneocytes.

Skin TARC/CCL17 increase precedes the development of childhood atopic dermatitis.

BACKGROUND: It is unknown whether skin biomarkers collected in infancy can predict the onset of atopic dermatitis (AD) and be used in future prevention trials to identify children at risk. OBJECTIVES: This study sought to examine whether skin biomarkers can predict AD during the first 2 years of life. METHODS: This study enrolled 300 term and 150 preterm children at birth and followed for AD until the age of 2 years. Skin tape strips were collected at 0 to 3 days and 2 months of age and analyzed for selected immune and barrier biomarkers. Hazard ratio (HR) with 95% confidence interval (CI) using Cox regression was calculated for the risk of AD. RESULTS: The 2-year prevalence of AD was 34.6% (99 of 286) and 21.2% (25 of 118) among term and preterm children, respectively. Skin biomarkers collected at birth did not predict AD. Elevated thymus- and activation-regulated chemokine/C-C motif chemokine ligand 17 -levels collected at 2 months of age increased the overall risk of AD (HR: 2.11; 95% CI: 1.36-3.26; P = .0008) and moderate-to-severe AD (HR: 4.97; 95% CI: 2.09-11.80; P = .0003). IL-8 and IL-18 predicted moderate-to-severe AD. Low filaggrin degradation product levels increased the risk of AD (HR: 2.04; 95% CI: 1.32-3.15; P = .001). Elevated biomarker levels at 2 months predicted AD at other skin sites and many months after collection. CONCLUSIONS: This study showed that noninvasively collected skin biomarkers of barrier and immune pathways can precede the onset of AD.

Stratum corneum cytokine levels in mycosis fungoides.

Mycosis fungoides (MF) is characterised by malignant CD4+ T-cell infiltrates in the skin. The functional characteristics of the malignant T cells and their interaction with the tumor immune microenvironment is largely unknown. We performed tape stripping of the stratum corneum (SC), a non-invasive technique, to gain insight into the cytokine secretion patterns in MF skin lesions. In addition, we assessed whether the SC cytokine profile of MF lesions is distinct from that of atopic dermatitis (AD) lesions. We compared nine cytokine levels in 20 patients with MF, 10 patients with AD and 10 healthy controls. In patients with MF and AD, lesional SC levels of IL-8 and MMP9 were significantly higher than in non-lesional SC and in healthy controls. VEGFα was significantly higher in lesional MF and AD skin than in healthy controls. The SC levels of IL-1α were significantly lower in MF and AD lesions than in healthy controls. There was no specific cytokine profile or inflammation pattern that could reliably distinguish MF from AD. In conclusion, in lesional SC of MF patients, pro-inflammatory cytokines can be detected. As a diagnostic method, tape stripping of lesional SC cannot discriminate MF skin from AD skin.

Skin biomarkers predict development of atopic dermatitis in infancy.

BACKGROUND: There is currently no insight into biomarkers that can predict the onset of pediatric atopic dermatitis (AD). METHODS: Nested in a prospective birth cohort study that examined the occurrence of physician-diagnosed AD in 300 children, 44 random children with onset of AD in the first year of life were matched on sex and season of birth with 44 children who did not develop AD. Natural moisturizing factor (NMF), corneocyte surface protrusions, cytokines, free sphingoid bases (SBs) of different chain lengths and their ceramides were analyzed from tape strips collected at 2 months of age before onset of AD using liquid chromatography, atomic force microscopy, multiplex immunoassay, and liquid chromatography mass spectrometry, respectively. RESULTS: Significant alterations were observed for four lipid markers, with phytosphingosine ([P]) levels being significantly lower in children who developed AD compared with children who did not (median 240 pmol/mg vs. 540 pmol/mg, p < 0.001). The two groups of children differed in the relative amounts of SB of different chain lengths (C17, C18 and C20). Thymus- and activation-regulated chemokine (TARC/CCL17) was slightly higher in children who developed AD, whereas NMF and corneocyte surface texture were similar. AD severity assessed by the eczema area and severity index (EASI) at disease onset was 4.2 (2.0;7.2). [P] had the highest prediction accuracy among the biomarkers (75.6%), whereas the combination of 5 lipid ratios gave an accuracy of 89.4%. CONCLUSION: This study showed that levels and SB chain length were altered in infants who later developed AD, and that TARC/CCL17 levels were higher.

Effects of topical corticosteroid versus tacrolimus on insulin sensitivity and bone homeostasis in adults with atopic dermatitis-A randomized controlled study.

INTRODUCTION: Topical corticosteroids (TCS), used to treat atopic dermatitis (AD), have been associated with type 2 diabetes and osteoporosis in epidemiological studies, possibly explained by systemic absorption. OBJECTIVES: We examined whether intensive daily whole-body TCS treatment over 2 weeks followed by twice weekly application for 4 weeks could elicit insulin resistance and increase bone resorption in adults with AD. METHODS: A randomized parallel-group double-blind double-dummy non-corticosteroid-based active comparator study design was completed in Copenhagen, Denmark. Thirty-six non-obese, non-diabetic adults with moderate-to-severe AD were randomized to whole-body treatment with betamethasone 17-valerate 0.1% plus a vehicle once daily or tacrolimus 0.1% twice daily after washout. Insulin sensitivity assessed by the hyperinsulinemic-euglycemic clamp combined with tracer infusions and biomarkers of bone formation (P1NP) and resorption (CTX) were evaluated at baseline, after 2 weeks of daily treatment and after further 4 weeks of twice-weekly maintenance treatment. RESULTS: AD severity improved with both treatments and systemic inflammation was reduced. After 2 weeks, we observed similar increase in peripheral insulin sensitivity with use of betamethasone (n = 18) and tacrolimus (n = 18). Bone resorption biomarker, CTX, was unchanged, while bone formation marker, P1NP, decreased after betamethasone treatment after both 2 and 6 weeks but remained unchanged in the tacrolimus arm. CONCLUSIONS: Whole-body treatment with TCS leads to systemic exposure but appears not to compromise glucose metabolism during short-term use, which may be a result of reduced systemic inflammatory activity. The negative impact on bone formation could be regarded an adverse effect of TCS.

The association between Staphylococcus aureus colonization on cheek skin at 2†months and subsequent atopic dermatitis in a prospective birth cohort.

BACKGROUND: Staphylococcus aureus may worsen already established atopic dermatitis (AD), but its primary role in the aetiopathogenesis and severity of AD is unclear. OBJECTIVES: To compare the prevalence of S. aureus colonization in early infancy in children who developed AD during the first 2 years of life with children who did not. METHODS: In this prospective birth cohort study, which included 450 infants, we analysed bacterial swabs collected from cheek skin at 0 and 2 months of age. The development of AD, and its severity, was diagnosed by a physician and monitored prospectively for 2 years. Information on parental atopy, filaggrin gene mutation status and use of antibiotics and emollients was included in the analyses. RESULTS: At birth, the occurrence of S. aureus colonization was similar in infants who developed subsequent AD and those who did not. At 2 months of age, S. aureus colonization was more common in children who later developed AD (adjusted hazard ratio 1.97, 95% confidence interval 1.21-3.19; P = 0.006). No association was found between S. aureus colonization and AD severity or age at onset. CONCLUSIONS: It remains unknown whether colonization with S. aureus may directly increase the risk of AD, or whether it should be considered as secondary to skin barrier impairment or a skewed immune activity, but according to our findings, S. aureus colonization is more commonly increased at 2 months of age in children who later developed AD.

Inflammatory, oxidative and DNA damage status in vegetarians: is the future of human diet green?

The health benefit of a vegetarian diet is still under debate as it may result in a higher intake of some beneficial micronutrients, while others may be reduced, thus influencing various metabolic pathways and health-related biomarkers. This scoping review discusses inflammatory, oxidative and DNA damage status in vegetarians and vegans compared to omnivores. Most of the reviewed studies indicated favorable effects of a vegetarian diet on oxidative status compared to omnivores but did not clearly associate particular dietary habits to genome damage. The evidence on the effect of vegetarian diet on the inflammatory and immunological biomarkers is poor, which could at least partly be explained by methodological constraints such as small sample size, short duration of vegetarianism and inconsistent definitions of the omnivorous diet. The only inflammatory biomarker that seems to be associated with the vegetarian diet was inflammatory mediator C-reactive protein, which in several studies showed lower values in vegetarians as compared to omnivores. There were very few studies on immunological markers and the results on the difference between vegetarians and omnivores were inconclusive. Although several biomarkers involved in oxidative stress and inflammation showed a beneficial association with the vegetarian diet, further research in well-defined and sufficiently sized cohorts is needed to provide more evidence.

Work-related and personal risk factors for occupational contact dermatitis: A systematic review of the literature with meta-analysis.

The objective of this review is to identify work-related and personal risk factors for contact dermatitis (CD), and assess their association with this frequently occurring occupational disease. A systematic review of the literature from 1990 to June 2, 2020, was conducted using Medline and Embase. Prospective cohort and case-control studies were included, and meta-analyses were conducted when feasible. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation. Twenty-nine studies were identified, comprising 26 study populations and with a total of 846 209 participants investigating 52 risk factors for CD. Meta-analyses were performed for five risk factors, all of them for irritant contact dermatitis (ICD). Moderate-quality evidence was found for associations between wet work and ICD (OR: 1.56, 95%CI: 1.21-2.01). High-quality evidence was found for the association between atopic dermatitis and ICD (OR: 2.44, 95%CI: 1.89-3.15). There was no evidence for an association between ICD and sex or history of hand dermatitis, respiratory and mucosal atopy. In conclusion, several work-related and personal risk factors associated with CD were identified. Our data emphasize the need for the assessment of both, work-related and personal, risk factors to prevent occupational CD.

Systematic review on skin adverse effects of important hazardous hair cosmetic ingredients with a focus on hairdressers.

BACKGROUND: The burden of occupational hand eczema in hairdressers is high, and (partly strong) allergens abound in the hair cosmetic products they use. OBJECTIVES: To systematically review published evidence concerning contact allergy to an indicative list of active ingredients of hair cosmetics, namely, p-phenylenediamine (PPD), toluene-2,5-diamine (PTD), persulfates, mostly ammonium persulfate (APS), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG), concerning the prevalence of sensitization, particularly in terms of a comparison (relative risk; RR) between hairdressers and non-hairdressers. METHODS: Following a PROSPERO-registered and published protocol, eligible literature published from 2000 to February 2021 was identified, yielding 322 publications, and extracted in standardized publication record forms, also considering risk of bias. RESULTS: Based on 141 publications, the contact allergy prevalence to PPD was 4.3% (95% CI: 3.8-4.9%) in consecutively patch tested patients. Other ingredients were mostly tested in an aimed fashion, yielding variable, and partly high contact allergy prevalences. Where possible, the RR was calculated, yielding an average increased sensitization risk in hairdressers of between 5.4 (PPD) and 3.4 (ATG). Additional evidence related to immediate-type hypersensitivity, experimental results, exposures, and information from case reports was qualitatively synthesized. CONCLUSIONS: An excess risk of contact allergy is clearly evident from the pooled published evidence from the last 20 years. This should prompt an improvement in working conditions and product safety.

Assessment of biomarkers in pediatric atopic dermatitis by tape strips and skin biopsies.

BACKGROUND: The cytokine profile of atopic dermatitis (AD) depends on age, ethnicity, and disease severity. This study examined biomarkers in children with AD collected by tape strips and skin biopsies, and examined whether the levels differed with filaggrin genotype, disease severity, and food allergy. METHODS: Twenty-five children aged 2-14 years with AD were clinically examined. Skin biopsies were collected from lesional skin and tape strips were collected from lesional and non-lesional skin. We analyzed natural moisturizing factor (NMF) and 17 immune markers represented by mRNA levels in skin biopsies and protein levels in tape strips. Common filaggrin gene mutations were examined in all children. RESULTS: The cytokine profile in lesional skin was dominated by a T helper (Th) 2 response in skin biopsies, and by a general increase in innate inflammation markers (interleukin (IL)-1α, IL-1ß, IL-8, IL-18) along with TARC and CTACK in tape strips. The levels of TARC, CTACK, IL-8, IL-18 showed significant correlation with AD severity in both lesional and non-lesional tape stripped skin, while no significant correlations were observed in skin biopsy data. In tape strips from lesional and non-lesional skin, the levels of NMF and selected cytokines differed significantly between children with and without FLG mutations and food allergy. CONCLUSION: Sampling of the stratum corneum with non-invasive tape strips can be used to identify biomarkers that are associated with disease severity, food allergy and FLG mutations. Skin biopsies showed robust Th2 signature but was inferior for association analysis regarding severity.

Children with atopic dermatitis show increased activity of ß-glucocerebrosidase and stratum corneum levels of glucosylcholesterol that are strongly related to the local cytokine milieu.

BACKGROUND: Atopic dermatitis (AD) is characterized by immune dysregulations and an impaired skin barrier, including abnormalities in lipid organization. In the stratum corneum (SC), ß-glucocerebrosidase (GBA) mediates transformation of glucosylceramide (GlcCER) into ceramide (CER) and cholesterol into glucosylcholesterol (GlcChol). Alteration in GBA activity might contribute to skin barrier defects in AD. OBJECTIVES: To investigate GBA activity in the SC of children with AD before and after topical corticosteroid therapy and to compare it with healthy controls; to determine SC levels of GlcCER- and CER-containing hydroxysphingosine base (GlcCER[H] and CER[H], respectively) and GlcChol; and to relate them to disease severity, skin barrier function and the local cytokine milieu. METHODS: Lipid markers and cytokines of innate, T helper 1 and T helper 2 immunity were determined in SC collected from healthy children and from clinically unaffected skin of children with AD, before and after 6 weeks of therapy with topical corticosteroids. AD severity was assessed by Scoring Atopic Dermatitis and skin barrier function by transepidermal water loss (TEWL). RESULTS: Baseline GBA activity and GlcChol levels were increased in children with AD but declined after therapy. CER[H] levels and the CER[H] to GlcCER[H] ratio were increased in AD. GBA activity and GlcChol correlated with TEWL and levels of multiple cytokines, especially interleukin-1α and interleukin-18. GlcChol was strongly associated with disease severity. CONCLUSIONS: We show increased GBA activity and levels of GlcChol in AD. Our data suggest an important role of inflammation in disturbed lipid processing. GBA activity or GlcChol might be useful biomarkers in the monitoring of therapeutic responses in AD. What is already known about this topic? Patients with atopic dermatitis (AD) have a reduced skin barrier, mainly caused by altered lipid organization. The mechanisms underlying these lipid anomalies are not fully understood but likely reflect both genetic abnormalities in AD skin and the local cutaneous inflammatory environment. What does this study add? We show increased activity of the ceramide-generating enzyme ß-glucocerebrosidase in AD. Activity of this enzyme was correlated with the local cytokine milieu and declined after local corticosteroid therapy. We show that glucosylcholesterol levels in the stratum corneum are increased in AD. The function of glucosylcholesterol and the physiological consequences of increased levels are not clear yet; however, its levels were strongly correlated with skin barrier function: high transepidermal water loss strongly correlated with high levels of glucosylcholesterol. What is the translational message? Correction of cutaneous inflammation largely restores alterations in lipid metabolism in the stratum corneum of infants with AD.

Differences in Occurrence, Risk Factors and Severity of Early-onset Atopic Dermatitis among Preterm and Term Children.

This prospective birth cohort followed 150 preterm and 300 term newborns during the first year of life to assess possible differences in risk factors, age at onset, anatomical location, and severity of atopic dermatitis. Atopic dermatitis was diagnosed clinically, and severity was assessed using Eczema Area Severity Index (EASI). DNA was analysed for filaggrin gene mutations. Parents were asked about environmental exposures and emollient use. Atopic dermatitis during the first year of life was observed in 21.2% of children and was more common in term children compared with preterm children (26.7% vs 11.7%, p < 0.001), with lower age of onset (4 vs 6 months, p < 0.05) and more severe disease at onset (EASI: 4.8 vs 0.4, p < 0.0005). Environmental risk factors for atopic dermatitis were essentially similar for preterm and term born children, apart from winter and autumn births. Filaggrin gene mutations were less common in preterm than term children (4.1% vs 9.2%, p = 0.06).

Stratum corneum biomarkers after in vivo repeated exposure to sub-erythemal dosages of ultraviolet radiation in unprotected and sunscreen (SPF 50+) protected skin.

BACKGROUND: There is a need for non-invasive biomarkers to assess in vivo efficacy of protective measures aiming at reducing ultraviolet radiation (UVR) exposure. Stratum corneum (SC) biomarkers showed to be promising markers for internal UVR dose and immune response. PURPOSE: To establish a dose-response relationship for SC biomarkers and explore their suitability for in vivo assessment of the blocking effect of two sunscreens with a high sun protection factor (SPF) (50+). METHODS: Twelve volunteers were exposed to a broad-spectrum UVB (280-320 nm), five times a week, during one week. Unprotected back skin was irradiated with 0.24, 0.48, 0.72 and 1.44 standard erythema dose (SED) and sunscreen-protected skin with 3.6 SED. SC samples for determination of the relative amount of cis-urocanic acid (cUCA) and thirteen immunological makers including cytokines and matrix metalloproteinases (MMP) were collected after each irradiation. RESULTS: cUCA sharply increased after the first irradiation in a dose-dependent fashion. However, it levelled-off after subsequent exposures and reached a plateau for the highest UV-dose after the third irradiation. None of the immunological markers showed dose-dependency. However, MMP-9, IL-1ß and CCL27 increased gradually from baseline during repetitive exposures to the highest UV-dose. Assessed from cUCA, both sunscreens blocked >98% of the applied UV-dose. CONCLUSIONS: cUCA is a sensitive, non-invasive marker of the internal UVR dose enabling in vivo assessment of the blocking effect of high SPF sunscreens in the UVB-region. Immunological SC markers show low sensitivity in detecting immune response at sub-erythemal UVR dosages, suggesting they might be suitable only at higher and/or repetitive UVR exposure.

Risk communication about work-related stress disorders in healthcare workers: a scoping review.

PURPOSES: Healthcare workers are at risk of stress-related disorders. Risk communication can be an effective preventive health measure for some health risks, but is not yet common in the prevention of stress-related disorders in an occupational healthcare setting. The overall aim is to examine whether risk communication was part of interventions aimed at the prevention of stress-related disorders in healthcare workers. METHOD: We performed a scoping review using the framework of Arksey and O'Malley. We searched in Medline, Web of Science and PsychInfo for studies reporting on preventive interventions of stress-related disorders in healthcare workers between 2005 and December 2020. Studies were included when the intervention reported on at least one element of risk communication and one goal. We predefined four elements of risk communication: risk perception, communication of early stress symptoms, risk factors and prevention; and three goals: inform, stimulate informed decision-making and motivate action. RESULTS: We included 23 studies that described 17 interventions. None of the included interventions were primarily developed as risk communication interventions, but all addressed the goals. Two interventions used all four elements of risk communication. The prominent mode of delivery was face to face, mostly delivered by researchers. Early stress symptoms and risk factors were measured by surveys. CONCLUSIONS: Risk communication on risk factors and early signs of stress-related disorders is not that well studied and evaluated in an occupational healthcare setting. Overall, the content of the communication was not based on the risk perception of the healthcare workers, which limited the likelihood of them taking action.

Respiratory toxicity of persulphate salts and their adverse effects on airways in hairdressers: a systematic review.

OBJECTIVE: To review the literature on respiratory effects of persulfate salts (PS) or hair bleaches in hairdressers and animal models exploring mechanisms behind PS-induced asthma. METHODS: A systematic review according to the PRISMA guidelines was performed. Studies published from 2000 to July 2021 that fulfilled predefined eligibility criteria were retrieved. Data were not quantitatively synthesized due to the heterogeneity of study designs, outcomes and methods. RESULTS: Forty-two articles were included. PS are indicated as the main cause of occupational rhinitis and asthma in hairdressers, and one of the leading causes of occupational asthma in some European countries. Bleaching products are indicated as the most important factor for development of respiratory symptoms, lung function decline, and leaving the hairdressing profession. Risk estimates from a good quality prospective study showed up to 3.9 times higher risk for wheezing and breathlessness in hairdressers aged ≥ 40 years than in matched controls, and 20 times higher risk in hairdressers to develop respiratory symptoms from exposure to bleaching powder than controls. Pathophysiological mechanisms of the respiratory response to PS are not yet fully elucidated, but may include non-specific and specific immune responses. CONCLUSIONS: Hairdressing is associated with a wide spectrum of respiratory adverse effects, of which bleaching products were indicated as the most hazardous. Preventive measures for reducing inhalatory exposure to PS in hair salons should be re-evaluated, including adopting occupational exposure limits at EU level, and encouraging use of safer bleach formulations. PROSPERO REGISTRATION NUMBER: CRD42021238118.

Effects of skin washing frequency on the epidermal barrier function and inflammatory processes of the epidermis: An experimental study.

BACKGROUND: Increased hand hygiene measures during the COVID-19 pandemic have led to an increased quantum of hand eczema (HE). OBJECTIVES: To examine the effects of varying washing frequencies using current mild cleansing agents-alongside with the effect of a rehydrating cream-on the epidermal barrier function and inflammatory processes of the stratum corneum(SC). METHODS: Standardized skin washings on the volar aspects of the lower arms of skin-healthy volunteers were performed using the automated cleansing device either 5 or 11 times within 4 h for 60 s each with a standard cleanser, a lipid-containing syndet, or a lipid-containing syndet followed by one-time application of a rehydrating cream. Skin bioengineering parameters (transepidermal water loss, SC hydration, erythema, and SC pH) and biochemical/immunological parameters (interleukin-1α, interleukin-1α receptor antagonist and natural moisturizing factor) of SCsamples collected by tape stripping were assessed. RESULTS: All applied washing procedures provided comparable, mild effects on the epidermal barrier function and skin inflammation. CONCLUSION: Occupational skin cleansers seem to have improved regarding skin barrier damaging effects. To further corroborate this, a study design, modified on the basis of our findings, applying longer washing periods for consecutive days seems desirable.

Prevalence and incidence of hand eczema in hairdressers-A systematic review and meta-analysis of the published literature from 2000-2021.

BACKGROUND: Hairdressers are commonly affected by hand eczema (HE) due to skin hazardous exposure such as irritants and allergens in the work environment. OBJECTIVE: To give an overview of the current prevalence, incidence, and severity, as well as the pattern of debut and the contribution of atopic dermatitis on HE in hairdressers. METHODS: A systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines was performed. Studies published from 2000 to April 2021 that fulfilled predefined eligibility criteria were retrieved. RESULTS: A pooled lifetime prevalence of 38.2% (95% confidence interval [CI] 32.6-43.8), a pooled 1-year prevalence of 20.3% (95% CI 18.0-22.6), and a pooled point prevalence of 7.7% (95% CI 5.8-9.6) of HE was observed in hairdressers. The lifetime prevalence in fully trained hairdressers and hairdressing apprentices was almost identical. The pooled incidence rate of HE was 51.8 cases/1000 person-years (95% CI 42.6-61.0) and the pooled prevalence of atopic dermatitis was 18.1% (95% CI 13.6-22.5). CONCLUSION: HE is common in hairdressers and most hairdressers have debut during apprenticeship. The prevalence of atopic dermatitis in hairdressers is comparable with estimates in the general population, indicating that occupational exposures are the main factor in the increased prevalence of HE in hairdressers. This warrants a strategic and collective effort to prevent HE in hairdressers.

Differences between hairdressers and consumers in skin exposure to hair cosmetic products: A review.

Hairdressers are at high risk of developing occupational hand eczema. Opinions on the health and safety concerns of nonfood consumer products, such as cosmetics and their ingredients, consider the exposure of a "common consumer," which may not account for occupational exposure of hairdressers. As a result, there is a parlous scenario in which serious safety concerns about occupational exposures are present. The purpose of this review is to compare the frequency of exposure to various types of hair cosmetic products among hairdressers and consumers. Database searches for this review yielded a total of 229 articles; 7 publications were ultimately included. The analysis showed that-dependent on the task-hairdressers were exposed 4 to 78 times more than consumers to a wide spectrum of hair cosmetic products used in their daily working life, ranging from shampoos, conditioners, oxidative and nonoxidative hair colors, to bleaching agents. The highest frequency was found for coloring hair with oxidative hair color. Consumer use frequency does not appear to be appropriate for representing hairdresser exposure. The current standards do not effectively address the occupational risks associated with hairdressers' use of cosmetics. The findings of this study should cause current risk-assessment procedures to be reconsidered.