Notification of hand eczema as an occupational disease among Danish hairdressers: a national survey on patients' perception.

OBJECTIVES: Self-reported hand eczema was previously found under-reported as an occupational disease to the authorities among Danish hairdressers graduating from 1985 to 2007. This study investigates whether self-reported hand eczema among Danish hairdressers graduating from 2008 to 2018 is under-reported as an occupational disease to the authorities. METHODS: A cross-sectional study on all Danish hairdressers graduating from 2008 to 2018 was conducted. The participants were identified using information from the Danish Hairdressers' and Beauticians' Union. In May 2020, a self-administered survey on hand eczema was sent to all hairdressers. RESULTS: A response rate of 30.7% (1485/4830) was obtained. The lifetime prevalence of self-reported hand eczema was 40.1%, and 84.1% of hairdressers with hand eczema believed it to be occupational of whom 27.0% answered it was reported as an occupational disease to the authorities. Of hairdressers believing their hand eczema was occupational, consulting a doctor and answering it was reported as an occupational disease, 94.4% had consulted a dermatologist. The main reason for not reporting was 'I would probably not gain anything from it anyway' (40.0%). CONCLUSIONS: Based on hairdressers' perception, occupational hand eczema still seems to be an under-reported disease which may lead to underestimation of the problem and impair prevention, diagnosis and treatment.

Referral Pathways for Children with Atopic Diseases in Denmark.

Atopic diseases such as atopic dermatitis, food allergy, allergic rhinoconjunctivitis, and/or asthma are common. In Denmark, however, there are multiple referral pathways for these diseases in the healthcare system and they are poorly understood. To describe how children with atopic diseases navigate their way through the Danish healthcare system, a questionnaire was distributed to children aged ≤ 17 years, who were being treated for atopic diseases between August 2020 and June 2021, either by a practising specialist or a hospital department, in the Capital Region of Denmark. A total of 279 children completed the questionnaire and most were referred to a specialist or to a hospital by their general practitioner. No "common track" to hospital existed for patients with ≥ 3 atopic diseases. These patients were more often referred to a hospital compared with children with 2 atopic diseases or fewer (odds ratio [OR] 3.79; 95% CI 2.07-7.24). The primary determinants for hospital treatment were food allergy (OR 4.69; 95% CI 2.07-10.61) and asthma (OR 2.58; 95% CI 1.18-5.63). In conclusion, children with multiple atopic diseases were more likely to be referred to hospital departments than to practising specialists, mainly due to food allergies.

Inflammatory plasma signature of chronic hand eczema: Associations with aetiological and clinical subtypes.

BACKGROUND: Chronic hand eczema (CHE) is a highly prevalent, heterogeneous, skin disease that encompasses different aetiological and clinical subtypes. Severe CHE without atopic dermatitis has been associated with systemic inflammation; yet it remains unknown if specific CHE subtypes leave distinct, systemic, molecular signatures. OBJECTIVES: To characterize the inflammatory plasma signature of different aetiological and clinical CHE subtypes. METHODS: We assessed expression levels of 266 inflammatory and cardiovascular disease risk plasma proteins as well as filaggrin gene mutation status in 51 well-characterized CHE patients without concomitant atopic dermatitis and 40 healthy controls. Plasma protein expression was compared between aetiological and clinical CHE subgroups and controls both overall and according to clinical CHE severity. Correlation analyses for biomarkers, clinical and self-reported variables were performed. RESULTS: Very severe, chronic allergic contact dermatitis (ACD) on the hands was associated with a mixed Type 1/Type 2 systemic immune activation as compared with controls. Circulating levels of Type 1/Type 2 inflammatory biomarkers correlated positively with clinical disease severity among CHE patients with ACD. No biomarkers were found, that could discriminate between aetiological subtypes, for example, between ACD and irritant contact dermatitis. Hyperkeratotic CHE showed a distinct, non-atopic dermatitis-like, systemic footprint with upregulation of markers associated with Type 1 inflammation and tumour necrosis factor alpha, but not Type 2 inflammation. Increased levels of CCL19 and CXCL9/10 could discriminate hyperkeratotic CHE from both vesicular and chronic fissured CHE, whereas no difference was found between the latter two subtypes. CONCLUSION: Profiling of systemic biomarkers showed potential for identifying certain CHE subtypes. Peripheral blood levels of inflammatory biomarkers were associated and correlated with the clinical disease severity of chronic ACD on the hands, underlining that this is a systemic disease. We question whether hyperkeratotic CHE should be classified as eczema.

Association between atopic disease and vaccination granulomas: A nested case-control study.

BACKGROUND: Vaccination granulomas are observed in 1% of all children vaccinated with an aluminium-adsorbed vaccine. Most children with granulomas also have aluminium contact allergy (CA). CA and atopic diseases are both highly prevalent among children and may be associated. OBJECTIVE: To investigate the association between vaccination granulomas and atopic dermatitis (AD), asthma and rhinitis in children. METHODS: We sourced a cohort of all Danish children born from 2009 to 2017 and conducted a nested case-control study, with cases defined as children with vaccination granulomas, matched to controls 1:10 on sex, socioeconomic class, gestational age and season of birth. All cases and controls were vaccinated with aluminium-adsorbed vaccines and followed until their second birthday. We used conditional logistic regression to estimate the odds ratios (ORs). RESULTS: The study included 2171 cases with vaccination granulomas, and 21 710 controls. Children with a diagnosis of AD had a significantly higher risk of a vaccination granuloma (OR 1.50, 95% confidence intervals [CI] 1.25-1.80). No significant association was found between granulomas and asthma or rhinitis. The association between granulomas and AD was even higher in an additional sensitivity-analysis, following the children until their fourth birthday (OR 2.71, 95% CI 2.36-3.11). CONCLUSION: AD was significantly associated with vaccination granulomas, but not with other atopic diseases, within both the first 2 and 4 years of life.

Contact sensitization to fragrance mix I and fragrance mix II among European dermatitis patients: A systematic review.

BACKGROUND: Fragrance substances are a frequent cause of contact allergy worldwide. Fragrance exposure varies by sex, age and possibly country, influenced by cosmetic availability, environmental conditions and cultural practices. OBJECTIVES: To systematically review and gather prevalence of sensitization to fragrance mix I (FM I) and fragrance mix II (FM II) in consecutively patch-tested European dermatitis patients. METHOD: A total of 4134 publications on patch test results of European dermatitis patients, published from 1981 to 2022, were systematically reviewed according to a previously registered and published PROSPERO protocol. RESULTS: Eighty-four eligible original articles were analysed. Overall prevalence of sensitization to fragrance mix I (FM I) was 6.81% (95% CI: 6.37-7.28), and FM II was 3.64% (95% CI: 3.3-4.01). Sensitization to FM I was most prevalent in Central and Eastern Europe and to FM II in Western Europe. No clear time trends were observed. Among paediatric dermatitis patients, sensitization prevalence for FM I and FM II was 4.09% (95% CI: 3.37-4.96) and 2.17% (95% CI: 1.53-3.07). CONCLUSION: The frequency of positive patch test results for both FMI and FMII remains high. Sensitization is also prevalent among children. Enhanced regulation and labelling of cosmetic products play a vital role in averting exposure and sensitization to fragrance allergens.

Hand eczema in Danish adolescents-Beyond atopic dermatitis.

BACKGROUND: Hand eczema (HE) is a common inflammatory skin disease that may have serious consequences. The age of HE onset varies, but is estimated to be early- to mid-20s. However, very little is known about HE in childhood and adolescence. OBJECTIVE: We aimed to explore the epidemiology, aetiology and severity of HE among a random sample of Danish adolescents drawn from the general population. METHODS: The study was designed as a self-administered questionnaire study. An electronic questionnaire was sent to a random sample of 13 000 individuals aged 15-19 years. RESULTS: The point-prevalence, 1-year prevalence and life-time prevalence of HE among Danish adolescents was 4.9%, 12.1% and 18.3%, respectively. Among patients with a history of HE, 64.6% of cases were not associated with atopic dermatitis. Of all respondents, 60.2% were either part-time or full-time employed. Among respondents with current HE, 38.2% believed that the occupational exposures either caused or exacerbated the HE. CONCLUSION: We found a high prevalence of HE among Danish adolescents which raises concern. Knowing the potential consequences that HE may have, attention should be paid to the prevention of HE in adolescence, especially on occupational aspects and prevention of skin disease in young workers.

Severely compromised supply of patch test allergens in Europe hampers adequate diagnosis of occupational and non-occupational contact allergy. A European Society of Contact Dermatitis (ESCD), European Academy of Allergy and Clinical Immunology (EAACI), European Academy of Dermatology and Venereology (EADV) task forces 'Contact Dermatitis' and 'Occupational Skin Disease' position paper.

Patch testing is the only clinically applicable diagnostic method for Type IV allergy. The availability of Type IV patch test (PT) allergens in Europe, however, is currently scarce. This severely compromises adequate diagnostics of contact allergy, leading to serious consequences for the affected patients. Against this background, the European Society of Contact Dermatitis (ESCD) has created a task force (TF) (i) to explore the current availability of PT substances in different member states, (ii) to highlight some of the unique characteristics of Type IV vs. other allergens and (iii) to suggest ways forward to promote and ensure availability of high-quality patch testing substances for the diagnosis of Type IV allergies throughout Europe. The suggestions of the TF on how to improve the availability of PT allergens are supported by the ESCD, the European Academy of Allergy and Clinical Immunology, and the European Academy of Dermatology and Venereology and intend to provide potential means to resolve the present medical crisis.

Adverse reactions after oral provocation with aluminium in children with vaccination granulomas and aluminium contact allergy.

BACKGROUND: According to their parents, some children with aluminium contact allergy and vaccination granulomas may react to aluminium-containing foods by developing dermatitis, granuloma itch and subjective symptoms. OBJECTIVES: The objective of this study is to determine whether oral intake of aluminium-containing pancakes can cause adverse events and/or systemic contact dermatitis (SCD) in children with vaccination granulomas and aluminium contact allergy. PATIENTS/METHODS: A total of 15 children aged 3-9 years (mean age, 5 years) with vaccination granulomas and positive patch-test results to aluminium chloride hexahydrate 2%/10% pet. completed a 3-week blinded randomized controlled crossover oral aluminium/placebo provocation study with pancakes. Granuloma itch and other subjective symptoms were evaluated daily on a visual analogue scale (VAS). Dermatitis was evaluated by the primary investigator, and sleep patterns were tracked with an electronic device. Aluminium bioavailability was assessed by measuring aluminium excretion in the urine. The children served as their own controls with the placebo provocations. RESULTS: All 15 children completed the study. The mean VAS scores were slightly higher during aluminium provocations compared with placebo for granuloma itch (mean VAS, 1.5 vs. 1.4, p = 0.6) but identical for other subjective symptoms (0.6 vs. 0.6, p = 1). There were no differences in sleep patterns and no significant correlation between urinary aluminium excretion and symptom severity. Three children developed a symmetrical rash on the face or buttocks on day 4 of the aluminium provocations, but not during placebo provocations. CONCLUSIONS: No difference was found between oral aluminium intake and the occurrence of subjective symptoms and granuloma itch, but on a case-basis oral aluminium may be associated with the development of systemic contact dermatitis.

Topical eye medications causing allergic contact dermatitis.

BACKGROUND: Allergic contact dermatitis (ACD) in the eye region caused by topical eye medications is difficult to diagnose and may be overlooked. OBJECTIVE: To study the characteristics and causative agents in patients with ACD caused by topical eye medications in a Danish tertiary dermatology department. METHODS: A retrospective study of 318 patients, patch tested between 2013 and 2021 due to suspected ACD to topical eye medications. All patients were tested with a locally developed eye medication series, some were additionally tested with suspected eye medications. Medical records were studied in patch test positive patients. RESULTS: Contact allergy to a topical eye allergen/medication was found in 12.9% (n = 41) of 318 patients, and culprit allergens were phenylephrine (6.9%), timolol (2.5%) and ketotifen (1.6%). Patch test positive patients were often previously diagnosed with cataract (29.3%) or glaucoma (24.4%), and the majority reported more than one previous reaction. Initial symptoms were oedema (56.0%), erythema (48.8%) and dermatitis (31.7%) in the eye region, and facial dermatitis was also seen. CONCLUSIONS: Patients with symptoms from the eye region who have been using topical eye medications should be patch tested with ingredients from commonly used eye medications supplemented by the products tested 'as is'.

Chronic hand eczema: A prevalent disease in the general population associated with reduced quality of life and poor overall health measures.

BACKGROUND: The impact of hand eczema (HE) on Health-Related Quality of Life (HRQoL) has only been sparsely studied in a general population setting, and never by use of the disease specific Quality Of Life in Hand eczema Questionnaire (QOLHEQ). OBJECTIVES: To examine the HRQoL of unselected individuals with HE using the QOLHEQ. Further, to provide prevalence estimates of severe and chronic HE (CHE), and to contrast overall health related outcomes between individuals with and without HE. METHODS: In this nationwide, cross-sectional study a questionnaire covering questions on HE related outcomes, and overall health was sent to a random sample of 100 000 Danish adults via a secure digital mailbox, linked to their unique civil registration numbers. Data on demographic characteristics were retrieved from the civil registration system. Individuals reporting HE, further answered the QOLHEQ and other disease specific questions. RESULTS: The response rate was 42.7% (n = 42 691). Total estimates of lifetime, 1-year and point prevalences of HE were 24.4%, 13.3% and 5.8%. Of individuals reporting a 1-year prevalence, 35.1% reported moderate-severe disease and 82.6% CHE. Individuals with HE were more likely to report less good or poor overall health, and sick leave (any reason), compared to those without. In the 2176 (92.5%) with current HE who completed the QOLHEQ, median QOLHEQ scores corresponded to a moderate impairment of the symptoms and treatment and prevention domains and a slight impairment overall and for the emotions and functioning domains. Factors that were strongly associated with moderate to severe HRQoL impairment included severe, chronic and occupational HE as well as female sex. CONCLUSIONS: HE is highly prevalent, bears a considerable burden on society and significantly affects the lives of impacted individuals. Our findings indicate a necessity for targeted prevention aimed at high-risk groups, and support and treatment for those most affected.

Fragrance allergens in cosmetic products marketed for children in Denmark.

BACKGROUND: Fragrances are among the most common contact allergens in children. Cosmetic products are the most frequent source of skin exposure. OBJECTIVE: To investigate exposure to fragrance allergens among Danish children, based on a sample of 1179 cosmetic products marketed for children. METHODS: Information regarding cosmetic products marketed to children was obtained using a non-profit smartphone application registry, with data from December 2015 to November 2022. RESULTS: The number of validated products was 26 537, of which 1349 marketed for children. After elimination of duplicates, 1179 (4.4%) individual products remained. The majority 53.8% (634/1179) of the products were fragranced. The highest frequency of declared fragrances was found in 'Facial care'-products: 93.0% (80/86), of which 97.7% were lip balms. The highest number of labelled fragrances in one single product (n = 16) was found in a baby perfume. Fragrance mix I (FMI) or II (FMII) allergens were found in 25.3% (298/1179) of the products. Limonene and linalool were the two most frequently labelled fragrance allergens. CONCLUSION: Children can be exposed to a vast number of fragrance allergens from scented cosmetic products. Allergens from FM I and FMII are widely used in cosmetic products marketed to children. Patch testing with FMI and FMII remains relevant in children.

CD4+ T cells inhibit the generation of CD8+ epidermal-resident memory T cells directed against clinically relevant contact allergens.

BACKGROUND: CD8+ epidermal-resident memory T (TRM ) cells play central roles in local flare-up responses to experimental contact allergens by inducing massive influx of neutrophils to the epidermis upon allergen challenge. Whether similar immunopathogenic mechanisms are involved in the responses to clinically relevant contact allergens is unknown. METHODS: The immune response to cinnamal, ρ-phenylenediamine (PPD) and methylisothiazolinone (MI) was studied in a well-established mouse model for allergic contact dermatitis that includes formation of TRM cells by ELISA, flow cytometry, fluorescence microscopy analyses and cell depletion protocols. RESULTS: We show that the formation of CD4+ and CD8+ epidermal TRM cells and the inflammatory response are highly allergen-dependent. However, the magnitude of the flare-up responses correlated with the number of epidermal CD8+ TRM cells, CXCL1/CXCL2 release and recruitment of neutrophils to the epidermis. Finally, depletion of CD4+ T cells strongly enhanced the number of epidermal CD8+ TRM cells, the flare-up response and the epidermal infiltration of neutrophils for all allergens. CONCLUSION: As the first, this study demonstrates that clinically relevant contact allergens have the ability to generate pathogenic, epidermal CD8+ TRM cells that recruit neutrophils following re-exposure to the allergen, but that this normally is counteracted by the simultaneous induction of anti-inflammatory CD4+ T cells.

Novel insights into contact dermatitis.

Contact dermatitis is a common disease that is caused by repeated skin contact with contact allergens or irritants, resulting in allergic contact dermatitis (ACD) and/or irritant contact dermatitis. Attempts have been made to identify biomarkers to distinguish irritant and allergic patch test reactions, which could aid diagnosis. Some promising candidates have recently been identified, but verification and validation in clinical cases still need to be done. New causes of ACD are constantly being recognized. In this review, 10 new contact allergens from recent years, several relating to anti-aging products, have been identified. Frequent allergens causing considerable morbidity in the population, such as the preservative methylisothiazolinone, have been regulated in the European Union. A significant drop in the number of cases has been seen, whereas high rates are still occurring in other areas such as North America. Other frequent causes are fragrance allergens, especially the widely used terpenes and acrylates found in medical devices for control of diabetes. These represent unsolved problems. Recent advances in immunology have opened the way for a better understanding of the complexity of contact dermatitis, especially ACD-a disease that may be more heterogenous that previous understood, with several subtypes. With the rapidly evolving molecular understanding of ACD, the potential for development of new drugs for personalized treatment of contact dermatitis is considerable.

Occupational hand eczema reduces career length in hairdressers: a prospective cohort study of Danish hairdressers graduating from 1985 to 2007.

BACKGROUND: Occupational hand eczema (OHE) is common in hairdressers, and many leave the trade because of the disease. However, the exact impact of OHE on career length is unknown. OBJECTIVE: To assess the effect of OHE on career length and risk factors associated with leaving the trade because of OHE in hairdressers followed-up for up to 35 years. METHODS: A prospective cohort study of Danish hairdressers graduating between 1985 and 2007 (n=5219) was performed. A questionnaire was sent in 2009 and 2020. The Danish Labor Marked Supplementary Pension Scheme provided information on affiliation to the hairdressing profession. Career length was assessed by Kaplan-Meier analyses. RESULTS: The median survival time was 12.0 (95% CI 11.0 to 13.0) years in graduates with OHE and 14.0 (95% CI 12.6 to 15.4) years in graduates without OHE (p<0.001). Graduates with a frequency of hand eczema (HE) of 'once', 'several times' and 'almost all the time' had a median survival time of 20.0 (95% CI 14.6 to 25.4), 12.0 (95% CI 10.7 to 13.3) and 7.0 (95% CI 5.6 to 8.4) years, respectively. Graduates with OHE that left the trade (partly) because of HE constituted 11.7% of the study population. Factors associated with leaving the trade because of HE included a history of atopic dermatitis (adjusted OR (aOR) 2.2 (95% CI 1.2 to 4.0), a history of a positive patch test (aOR 5.1 (95% CI 2.3 to 11.0) and allergy to hair dyes (aOR 9.4 (95% CI 3.4 to 25.6). CONCLUSION: Career length is reduced in hairdressers with OHE, especially if frequently relapsing or caused by contact allergy, for example, to hair dyes.

Risk factors for granulomas in children following immunization with aluminium-adsorbed vaccines: A Danish population-based cohort study.

BACKGROUND: Aluminium-adsorbed vaccines may in some children cause severely itching nodules at the injection site, known as vaccination granulomas. OBJECTIVE: To investigate vaccine-, child- and maternal-level risk factors for the development of vaccination granulomas following immunization with aluminium-adsorbed vaccines. METHODS: A Danish population-based cohort study with 553 932 children born in Denmark from 1 January 2009 to 31 December 2018, vaccinated with an aluminium-adsorbed vaccine during the first year of life, followed until 31 December 2020. Poisson regression was used to estimate granuloma rate ratios according to the type of adjuvant, accumulated dose of aluminium, timing of vaccination appointments, sex, gestational age, having siblings with granulomas, maternal age and maternal ethnicity. RESULTS: We identified 1901 vaccination granuloma cases (absolute risk, 0.34%). Among vaccine level factors, revaccination (third vs. first vaccination appointment, adjusted rate ratio [RR] 1.26, 95% confidence interval [CI] 1.03-1.55), the specific adjuvant used (aluminium phosphate vs. hydroxide, RR 0.58, 95% CI 0.48-0.70) and dosage (≥1.0 mg vs. <1.0 mg, RR 1.34, 95% CI 1.19-1.52) were associated with risk of granulomas; the timing of vaccination appointments was not. Among child-level factors, female sex (vs. males, RR 1.12, 95% CI, 1.02-1.22), prematurity (vs. term birth, RR 0.71, 95% CI, 0.54-0.93) and having sibling(s) with granulomas (vs. no siblings with granulomas, RR 46.15, 95% CI, 33.67-63.26) were associated with risk of granulomas. Among maternal-level factors, non-Danish ethnicity (vs. Danish, RR 0.51, 95% CI, 0.42-0.63) and young maternal age (<20 years vs. 20-39 years, RR 0.46, 95% CI 0.25-0.83) were associated with risk of granulomas. CONCLUSIONS: Several risk factors for vaccination granulomas at the vaccine, child and maternal levels, were identified. Reducing the dose of aluminium or replacing aluminium hydroxide with aluminium phosphate could reduce the risk of granulomas. However, this must be balanced against the potential for reduced immunogenicity.

Allergic contact dermatitis from dyes used in the temple of spectacles.

BACKGROUND: We observed an increasing number of patients who presented with facial or retro-auricular dermatitis after skin contact with plastic spectacles or plastic covered temples. OBJECTIVES: To identify the allergens in plastic spectacles that may cause allergic contact dermatitis. METHODS: All patients with suspected allergic contact dermatitis to eyewear were tested with Solvent Orange 60 (SO60), four additionally with Solvent Yellow 14 (SY14), and five with scrapings from their own spectacles. In one case, a chemical analysis of the spectacles was performed to uncover the causative allergen. RESULTS: Three patients were allergic to SO60, two patients to SY14, and two patients were allergic to both SO60 and SY14. CONCLUSION: Patients with suspected allergic contact dermatitis from spectacles should be tested with SO60 and SY14, and based on findings from previous reports, also with Solvent Red 179.

Guidelines for diagnosis, prevention, and treatment of hand eczema.

BACKGROUND: Hand eczema is a common inflammatory skin disorder. Health care providers need continuously updated information about the management of hand eczema to ensure best treatment for their patients. OBJECTIVES: To update the European Society of Contact Dermatitis guideline on the diagnosis, prevention, and treatment on of hand eczema. METHOD: The Guideline Development Group (GDG) was established on behalf of the ESCD. A call for interest was launched via the ESCD website and via the ESCD members' mailing list. Appraisal of the evidence for therapeutic and preventive interventions was applied and a structured method of developing consensus was used and moderated by an external methodologist. The final guideline was approved by the ESCD executive committee and was in external review on the ESCD webpage for 1 month. RESULTS: Consensus was achieved for several statements and management strategies. CONCLUSION: The updated guideline should improve management of hand eczema.

Skin dysbiosis in the microbiome in atopic dermatitis is site-specific and involves bacteria, fungus and virus.

BACKGROUND: Microbial dysbiosis with increased Staphylococcus aureus (S. aureus) colonization on the skin is a hallmark of atopic dermatitis (AD), however most microbiome studies focus on bacteria in the flexures and the microbial composition at other body sites have not been studied systematically. OBJECTIVES: The aim of the study is to characterize the skin microbiome, including bacteria, fungi and virus, at different body sites in relation to AD, lesional state, and S. aureus colonization, and to test whether the nares could be a reservoir for S. aureus strain colonization. METHODS: Using shotgun metagenomics we characterized microbial compositions from 14 well defined skin sites from 10 patients with AD and 5 healthy controls. RESULTS: We found clear differences in microbial composition between AD and controls at multiple skin sites, most pronounced on the flexures and neck. The flexures exhibited lower alpha-diversity and were colonized by S. aureus, accompanied by S. epidermidis in lesions. Malassezia species were absent on the neck in AD. Virus mostly constituted Propionibacterium and Staphylococcus phages, with increased abundance of Propionibacterium phages PHL041 and PHL092 and Staphylococcus epidermidis phages CNPH82 and PH15 in AD. In lesional samples, both the genus Staphylococcus and Staphylococcus phages were more abundant. S. aureus abundance was higher across all skin sites except from the feet. In samples where S. aureus was highly abundant, lower abundances of S. hominis and Cutibacterium acnes were observed. M. osloensis and M. luteus were more abundant in AD. By single nucleotide variant analysis of S. aureus we found strains to be subject specific. On skin sites some S. aureus strains were similar and some dissimilar to the ones in the nares. CONCLUSIONS: Our data indicate a global and site-specific dysbiosis in AD, involving both bacteria, fungus and virus. When defining targeted treatment clinicians should both consider the individual and skin site and future research into potential crosstalk between microbiota in AD yields high potential.

Aluminium contact allergy without vaccination granulomas: A systematic review and meta-analysis.

Aluminium contact allergy is mainly seen as granulomas following immunization with aluminium-adsorbed vaccines and contact allergy following epicutaneous exposure may be overlooked. To investigate the prevalence of aluminium allergy confirmed by patch testing, with no association with vaccination granulomas, and explore whether epicutaneous exposure to aluminium can contribute to allergic contact dermatitis. Two authors independently searched PubMed and MEDLINE (OVID) for case studies on contact allergy to aluminium proven by patch testing. Age-stratified meta-analyses to calculate the pooled prevalence were performed. Twenty-five studies describing a total of 73 cases were included in the review. Seven studies were suitable for meta-analyses. The prevalence of aluminium contact allergy was 5.61% (95% confidence interval [CI] 0.12%-11.08%) for children and 0.36% (95% CI 0.04%-0.67%) for adults. The studies described a variety of epicutaneous exposures, where metallic aluminium, topical medicaments, and deodorants were the main sources. Aluminium sensitization without a known exposure source was described in 10 of the 25 articles. The prevalence of aluminium contact allergy in the general public may be higher than expected and not solely related to vaccination granulomas. However, the clinical relevance is rare if not related to granulomas.

Epidermal T cell subsets-Effect of age and antigen exposure in humans and mice.

BACKGROUND: Epidermal T cells play a central role in immune surveillance and in inflammatory skin diseases. Major differences in the epidermal T cell composition are found between adult humans and antigen-inexperienced laboratory mice. Whether this is due to inborn species differences, to different environmental exposures, or a combination of the two is a matter of debate. OBJECTIVES: To investigate the role of age and exposure to antigens on epidermal T cell subsets in human and mouse skin. METHODS: We isolated T cells from the epidermis from 19 infants and 26 adults, and determined the frequency of CD4+ and CD8+ αß T cells and γδ T cells by flow cytometry. In addition, we determined the epidermal T cell composition in antigen-inexperienced and antigen-experienced mice. RESULTS: We found that humans are born with very few epidermal T cells. The number increases and the composition changes with age. In antigen-inexperienced mice, the epidermal T cell composition is unaffected by age, but it is dramatically affected by antigen exposure. CONCLUSION: Taken together, we show that antigen exposure, as opposed to age, is the major factor determining the composition of epidermal T cells, suggesting that the skin of antigen-experienced mice better reflects the immunological conditions in human skin.