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Ammonium persulfate (APS), an oxidizing agent used in hair products, manufacturing, and pool/spa water, can cause skin reactions, including allergic contact dermatitis.To characterize positive patch test reactions to APS (2.5% petrolatum).Retrospective analysis of patients tested to the North American Contact Dermatitis Group screening series from 2015 to 2018.Of 10,526 patients, 193 (1.8%) had positive patch test reactions to APS. Compared with APS-negative patients, APS-positive patients were significantly more likely to be male (43.2% vs 28.0%; P .0001); have primary hand dermatitis (30.2% vs 22.0%; P = .0064), scattered generalized dermatitis (25.5% vs 17.9%; P = .0064), or trunk dermatitis (8.9% vs 4.9%; P = .0123); and have dermatitis that is occupationally related (22.2% vs 10.9%; P .0001). More than half of the APS-positive reactions were currently relevant (57.0%); 19 (9.8%) were related to occupation, especially hairdressers (68.4%). Swimming pools/spas (23.3%) and hair care products (19.2%) were the most common sources of APS.Immediate reactions and follow-up testing were not captured.The proportion of patients positive to APS was 1.8%. APS positivity was significantly associated with male sex and hand dermatitis. Swimming pool/spa chemicals were important sources of APS exposure.

There is a worldwide increase in food and nutrition related contact dermatitis, including irritant contact dermatitis, allergic contact dermatitis, systemic contact dermatitis, protein contact dermatitis, and photocontact dermatitis. A wide range of patients is affected by this condition, from those who consume certain foods as part of their diet to workers who handle food occupationally. Patch testing, analytical chemistry, and reporting may help in timely recognition of contact allergens. Elimination of exposure to the known food or supplement is imperative for treatment. Currently, more research is needed in order to better define the role that nutrition plays in contact dermatitis.

Social media platforms are increasingly used by patients to research and discuss medical problems.The aim of this study was to identify by whom, how frequently, and in what manner allergic contact dermatitis (ACD) is discussed on social media sites.Search terms "allergic contact dermatitis" and "contact dermatitis" were queried across Twitter, Instagram, Reddit, Facebook, YouTube, and Google search metrics. The frequency, content, and creators of the content were assessed.ACD content was identified on all platforms, generated by by patients, physicians, professional organizations, and companies. When comparing the volume of posts, more content was on Instagram than Twitter, particularly among patients. Patient support groups were identified on Facebook but not on Reddit. A formal analysis of YouTube videos found that the medical information presented in these videos was often of poor quality.Patch testing physicians should be aware that information on ACD exists across social media sites. While some content is generated by physicians, patients and industry groups also post and share material. Patch testing physicians should know that there is an opportunity to share ACD information, but they should also be aware that patients are posting and creating online support communities independent of physicians.Online support communities exist for patients with ACD on Facebook. Online information is of lower quality, with a mean QUEST quality score of 7.4/28 on reviewed YouTube videos. Of the five social media sites reviewed, patients are most active on Instagram, Reddit, and Facebook. Approximately 9000 Google searches per month are conducted using contact dermatitis-related search terms. Differences in terminology exist between physicians and non-physicians. While the most popular hashtag term was "contact dermatitis", physicians disproportionately authored posts tagged with "allergic contact dermatitis."

Background No biomarkers have been identified that can classify subtypes of hand eczema (HE). Although skin biopsies represent the golden standard for investigations of the skin, the invasive technique is not favorable when investigating skin from sensitive areas. Recent advances in the use of skin tape strips for molecular investigations enable non-invasive investigations of HE. Objective By using whole transcriptome sequencing (WTS), the molecular profile of HE according to different localizations on the hands, etiologies, and clinical/morphological subtypes was investigated. Methods Thirty adult, Danish HE patients, 12 with and 18 without concurrent atopic dermatitis (AD), as well as 16 controls were included. Tape strip samples were collected from lesional, non-lesional, and healthy skin. Total RNA was extracted, and WTS was performed. Results The largest molecular difference of HE patients with and without AD was found in non-lesional skin areas and included a downregulation of CXCL8 for HE patients without AD. Differences between allergic- and irritant contact dermatitis included promising epidermal biomarkers such as EPHA1. Conclusion Skin tape strip samples could be used to assess the gene expression profile of HE on different localizations of the hands. The skin tape strip method identified new molecular markers that showed promising result for the identification of HE subtypes. This article is protected by copyright. All rights reserved.

BACKGROUND Allergic contact dermatitis has considerable public health impact and causative haptens vary over time. OBJECTIVES To report the prevalence of contact allergy to allergens in the Swedish baseline series 2010 to 2017, as registered in the Swedish Patch Test Register. METHODS Results and demographic information for patients tested with the Swedish baseline series in 2010 to 2017 were analysed. RESULTS Data for 21 663 individuals (females 69%) were included. Females had significantly more positive patch tests (54% vs 40%). The reaction prevalence rates were highest for nickel sulfate (20.7%), fragrance mix I (7.1%), Myroxylon pereirae (6.9%), potassium dichromate (6.9%), cobalt chloride (6.8%), methylchloroisothiazolinone/methylisothiazolinone (MCI/MI; 6.4%), MI (3.7%), colophonium (3.5%), fragrance mix II (3.2%), and formaldehyde (3.2%). Myroxylon pereirae reaction prevalence increased from 5% in 2010 to 9% in 2017 and that for methyldibromo glutaronitrile from 3.1% to 4.6%. MCI/MI and MI reactions decreased in prevalence after 2014. Nickel reaction prevalence decreased among females aged 10 to 19 years. CONCLUSIONS Nickel remains the most common sensitizing agent, with reaction prevalence decreasing among females younger than 20 years. The changes in MCI/MI and MI reaction prevalence mirrored those in Europe. The register can reveal changes in contact allergy prevalence over time among patients patch tested in Sweden.

Thymic stromal lymphopoietin (TSLP), positioned at the top of the inflammatory cascade, is a key regulator that enhances allergic inflammatory responses by activating T helper type 2 (Th2) cells, Group 2 innate lymphoid cells (ILC2), and myeloid dendritic cells (mDCs) via the TSLP receptor (TSLPR). We evaluated the inhibitory effects of ASP7266, a novel recombinant fully human IgG1 monoclonal antibody against TSLPR, on TSLP signaling and inflammation. The inhibitory effects of ASP7266 and the control antibody tezepelumab on TSLP and TSLPR interactions were investigated using a proliferation assay with TSLP stimulation and a chemokine production assay. The pharmacological effects of ASP7266 were investigated by examining differentiation of naive CD4+ T cells, ILC2 cytokine production, and ascaris extract-induced skin allergic reaction in cynomolgus monkeys. ASP7266 potently inhibited TSLP-induced cell proliferation and C-C motif chemokine ligand 17 (CCL17) production. Furthermore, ASP7266 inhibited TSLP-stimulated mDC-mediated naive CD4+ T cell differentiation, and IL-5 production by lineage-negative peripheral blood mononuclear cells (PBMCs), which can be considered ILC2, in vitro. In sensitized monkeys, ASP7266 completely suppressed ascaris extract-induced allergic skin reactions. Based on these results, ASP7266, a novel human therapeutic antibody against TSLPR, is a potential therapy for patients with allergic diseases. Significance Statement TSLP, positioned at the top of the inflammatory cascade, plays a key role in various allergic diseases, including asthma, chronic rhinosinusitis with nasal polyposis, and atopic dermatitis. Here we show that the anti-TSLPR antibody, ASP7266, exhibited excellent pharmacological activity in preclinical studies. Therefore, ASP7266 has the potential to be a promising treatment option for patients with allergic disorders.

Differences in consumer product availability, distribution, and use may lead to national differences in contact sensitization frequencies. Objective The aim of the study was to describe the differences in contact allergy between the United States (US) and Canada. Methods This is a retrospective cross-sectional analysis of the North American Contact Dermatitis Group data from 2005 to 2016. Frequencies of demographics, clinical characteristics, positive reactions, trends, and occupations were calculated. Results A total of 28,640 patients underwent patch testing. At least 1 positive patch test was observed in 18,599 patients (US, 11,641 [66.5%]; Canada, 6958 [62.5%]). When comparing the 2 groups, US positive reactions were more likely to occur in male patients (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.31-1.49), older than 40 years (OR = 1.30, 95% CI = 1.22-1.38), Black (OR = 2.67, 95% CI = 2.24-3.19) or Hispanic race (OR = 3.53, 95% CI = 2.61-4.78), and/or patients with scattered generalized dermatitis (OR = 1.96, 95% CI = 1.80-2.13). They were less likely to occur in patients with eczema (OR = 0.61, 95% CI = 0.57-0.65) and Asian race (OR = 0.50, 95% CI = 0.44-0.56). Nickel (US, 16.0%; Canada, 22.4%) and methylisothiazolinone (US, 13.4%; Canada, 11.0%) were the top allergens. The third most frequent was neomycin (US, 11.7%) and fragrance mix I (Canada, 10.2%). Conclusions National differences in allergen prevalence and trends exist in North America.

Background Both human and mouse allergic contact dermatitis (ACD) frequently demonstrates a combined type 1 and type 2 immune response. However, the relative importance of type 2 immunity in this setting has been incompletely understood yet. Objective To explore an effector function of type 2 immunity in ACD with mixed type 1/type 2 immune response. Methods Gene expression characteristics of contact hypersensitivity (CHS) model was examined by quantitative polymerase chain reaction. Cytokine profile of T cells was analyzed by flow cytometry. The involvement of type 2 immunity was assessed by antibody-mediated cytokine neutralization and cell depletion. The role of specific subset of cutaneous dendritic cells was evaluated using diphtheria toxin-induced cell-depleting mouse strains. Results Oxazolone-induced CHS revealed a combination of type 1/type 2 gene expression. The severity of oxazolone-induced CHS was ameliorated by neutralization of IL-4 but not of IFN-γ, indicating that type 2 immunity plays a dominant effector function in this mixed type 1/type 2 model. Mechanistically, type 2 effector immunity was mounted by CD301b+Langeirn− dermal dendritic cells in part through thymic stromal lymphopoietin-interleukin 7 receptor alpha signaling-dependent manner. Conclusion Our findings suggest the clinical rationale for targeting type 2 immunity as a relevant therapeutic strategy for the mixed immune phenotype of ACD.

BACKGROUND: Contact allergy to oxidized (ox.) linalool and ox. limonene has been reported to have a high prevalence, raising the question of inclusion into the baseline series. However, several important issues should be clarified and further investigated before inclusion can be warranted.OBJECTIVES: To report the trends of ox. terpenes allergy in patients with dermatitis, features of the patch test reactions, and clinical characteristics of the patients.METHODS: A retrospective analysis of 5773 patients was performed. All patients were patch tested with baseline series, individual ingredients of fragrance mix I and II, ox. linalool, and ox. limonene from 2013 to 2020.RESULTS: The prevalence rates of contact allergy to ox. linalool and ox. limonene were 7.0% and 5.1%, respectively. Significantly increasing trends of contact allergy were observed. More than 95% of contact allergy cases were identified on Day 3/4. Patients with contact allergy to ox. linalool and ox. limonene were significantly younger than those with contact allergy to other fragrances and were predominantly female. Strong reactions were associated with older age and multiple fragrance allergies.CONCLUSIONS: Contact allergy to ox. linalool and ox. limonene is becoming increasingly important, and findings show intriguing features. More studies concerning the clinical relevance before recommending these substances for screening are required. (Less)

BACKGROUND: Contact allergy is increasingly recognized as being important in children with eczema. OBJECTIVES: To retrospectively analyse the patch test results in children over the past 10 years, aiming to (1) evaluate demographic characteristics and lesion locations, (2) describe frequencies of positive patch test reactions, and (3) investigate the relationship with atopic dermatitis (AD). METHODS: A total of 329 children were patch tested between January 2010 and December 2019 with the European (children) baseline series and/or other series, and the personal product(s) used. RESULTS: A total of 119 (36%) children presented with at least one positive reaction. Children with AD had a higher prevalence of positive reactions compared with the non-AD group (P = .002), but without statistically significant difference regarding sensitization to more than one hapten (P = .39). The face (20.2%), hands (19.3%), feet (16.8%), arms (12.6%), and body folds (10.9%) were the most common sites of primary localizations. The most frequent contact allergens were nickel sulfate and linalool hydroperoxide (both 16%), limonene hydroperoxide (13.5%), and para-phenylenediamine (10.9%). No statistically significant difference for nickel sulfate was found between the AD and non-AD group (P = .20). CONCLUSIONS: Contact allergy in children with eczema was frequently observed in our tertiary referral centre in Belgium as well, confirming the need for patch testing. ispartof: Contact Dermatitis vol:86 issue:1 pages:3-8 ispartof: location:England status: accepted

Background Adhesive skin materials have increasingly been used in orthopedic surgery. We aimed to compare the efficacy and safety of skin adhesive (2-octyl cyanoacrylate and polymer mesh, Dermabond Prineo) and interrupted polypropylene sutures for wound closure in patients undergoing total ankle arthroplasty (TAA). Methods We prospectively enrolled 107 consecutive patients (108 ankles) undergoing TAA and divided them into two groups: skin adhesive group (36 ankles) and suture group (72 ankles). The primary outcome assessment included wound complications and patient satisfaction for wound cosmesis. The secondary outcome assessment included duration of surgery, length of hospital stay, and the Ankle Osteoarthritis Scale (AOS) pain and disability score. Results There was one case of allergic contact dermatitis, three cases of wound dehiscence, and one case of superficial surgical site infection in the skin adhesive group. Among them, one case each with allergic contact dermatitis and wound dehiscence finally progressed to deep surgical site infection. Three cases of wound dehiscence were also reported in the suture group; however, there was no case of surgical site infection. Patient satisfaction for wound cosmesis was significantly higher in the skin adhesive group than in the suture group (p = 0.001). There was no statistically significant difference between the groups in terms of secondary outcomes (p > 0.05). Conclusions Although the use of Dermabond Prineo showed better patient satisfaction for wound cosmesis, it showed significantly high wound complication rates and no other clinical benefits compared to interrupted polypropylene suture in TAA. Our results suggest that awareness of the possibility of wound complications is necessary when Dermabond Prineo is used in TAA.

BACKGROUND Recent trends in the sensitization of construction workers show a decrease in potassium dichromate and an increase in epoxy resin sensitization. OBJECTIVES To present the trends of occupational contact allergy of construction workers in Greece from 2009 to 2018. METHODS We retrospectively reviewed the files of patients with eczema patch tested in our Contact Dermatitis Clinic who were construction workers. RESULTS A total of 191 construction workers initially reported contact dermatitis. Of these, 138 had occupation-relevant allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD). All patients were men. After being patch tested, 98 (71.0%) were diagnosed with ACD and 40 with ICD. Median duration of occupation till onset of ACD was 2 years (interquartile range [IQR] 0.8-7). The hands were the most common location for ACD (73.5%), followed by the trunk (39.8%), the legs (38.8%), and the face (11.2%). Of the patients, 74.6% had lesions affecting multiple body sites. Potassium dichromate (67%) was the most frequent allergen, followed by thiuram mix (37.4%) and cobalt chloride (31.8%). Sensitization to epoxy resins was lower (12.1%). CONCLUSION The sensitization pattern of Greek construction workers does not follow the trends in Central or Northern Europe, rather sharing attributes with less industrialized countries.

BACKGROUND Patch testing is the standard diagnostic tool for shoe allergic contact dermatitis (ACD). As shoe materials change over time, utilizing commercial allergen series might be ineffective. However, because testing with patients' shoe samples is laborious, its value is questioned. OBJECTIVE The aim of this study was to ascertain the benefits of patch testing with patients' shoes by comparing the frequencies of patch-test positivity of shoes and shoe-related allergens in baseline series for suspected shoe ACD patients. METHODS A retrospective study was conducted of patients with clinically suspected shoe ACD who underwent patch testing with baseline series and shoe samples 2000 to 2019. RESULTS Almost half of the cohort (77 of 178; 43.3%) was diagnosed with shoe ACD. Of those 77, 48 (62.3%) were positive to shoe-related allergens from the baseline series, whereas 53 (68.8%) were positive to their shoe materials. The prevalence of tests positive to shoe material but negative to shoe-related allergens was 29 of 77 (37.7%). The most common shoe-related allergens were potassium dichromate (7.9%), carba mix (6.8%), and mercapto mix (6.7%). CONCLUSIONS Patch testing with shoe materials increased the diagnostic yield by 37.7 percent. To diagnose shoe ACD, testing of shoe materials may compensate for unknown, scarce, or novel allergens not in the baseline series.

BACKGROUND Vitamin E (tocopherol) a naturally occurring mixture of antioxidants commonly used in topical skin care products, may cause allergic contact dermatitis. OBJECTIVE The aim of this study was to characterize positive patch test reactions to tocopherol and tocopherol acetate. METHODS This is a retrospective analysis of North American Contact Dermatitis Group patch test data to tocopherols (dl-α-tocopherol 100% and/or dl-α-tocopherol acetate 100%) from 2001 to 2016. RESULTS Of the 38,699 patients patch tested to tocopherol and/or tocopherol acetate, 349 (0.9%) had positive reactions; of these, 87.6% were currently relevant. Most (51.4%) were weak (+) and/or not related to occupation (99.1%). Compared with tocopherol-negative patients, tocopherol-positive individuals were more likely to be female (72.5% vs 67.2%, P = 0.0355), have a final primary diagnosis of allergic contact dermatitis (74.2% vs 52.6%, P < 0.0001), and have dermatitis in a scattered generalized distribution (23.8% vs 18.2%, P = 0.0072); they were also less likely to have hand involvement (16.6% vs 22.3%, P = 0.0064). The most common source of tocopherol was personal care products, especially moisturizers. CONCLUSIONS Positive patch test reactions to tocopherols were relatively rare given their widespread use. When positive, current clinical relevance was high. Tocopherol-positive patients were more likely to be female and presented with dermatitis on the face or in a scattered generalized pattern.

Background: Allergic contact dermatitis from glucose sensors may interfere with their ongoing application. Objective: To evaluate a series of Spanish patients with contact dermatitis to glucose sensors regarding former sources of contact allergens, patch test results, and outcomes from the ongoing use of the device. Methods: A series of patients with contact dermatitis from glucose sensors was investigated in eight dermatology departments across Spain (epidemiological features, brands, latency time to develop dermatitis, the ability to continue using the devices as well as the patch test results). Results: Thirty patients were evaluated (mean age 20.9 years). A total of 66.7% were children and 66.7% female. Ninety per cent used Freestyle Libre (FSL). Eight of 26 (30.8%) reacted to isobornyl acrylate (IBOA) and two of 20 (10.0%) to N,N dimethylacrylamide (DMAA). The mean latency time to develop dermatitis was 9 months. Sixteen of 29 (55.2%) patients continued using the same sensor causing the reaction. Thirteen of 29 (44.8%) patients were unable to continue using the sensor because of severe reactions. Of these, five were positive to IBOA, one to IBOA and DMAA, one to DMAA, one to colophony, and one to isopropyl alcohol wipes. In one patient, the outcome was unknown. Conclusion: The frequency of sensitisation to IBOA and DMAA, was lower than in other European series, but similar to a previously published Spanish article. Legislation requiring manufacturers to provide information regarding the composition of medical devices and cooperate with the investigations into contact dermatitis is urgently needed.

Hair cosmetics such as shampoos, hair dyes, bleaching agents or hair straightening creams contain frequent contact allergens. These can lead to allergic contact dermatitis especially in hairdressers, but also in their customers and in others who use hair products at home. While hairdressers suffer mainly from hand dermatitis, in customers and home-users, dermatitis primarily affects the head, neck and face. In this mini-review, we propose a diagnostic algorithm in two steps, based on patch testing, that can be used for the assessment of suspected hair product-induced contact dermatitis. In a first step, we recommend testing the German Contact Allergy Group (DKG) standard series, DKG ointment series, DKG preservative series, DKG hairdresser series, DKG fragrance series as well as (especially in hairdressers) the DKG rubber series. In a second step, if the culprit allergen cannot be identified with the help of the standardized test series and there is a well-founded suspicion, testing the patient's own products, such as shampoos, hair sprays and hair dyes, is recommended.

Allergic contact dermatitis (ACD) is a common inflammatory dermatosis characterized by persistent itch and pain after topical contact with reactive chemicals. Although it has been long recognized as a type-IV hypersensitivity, its complexity of pathophysiology mechanism makes it still a clinical aporia in treatment. In this study, we aimed to identify crucial proteins involved in the nociceptive sensation of ACD. Based on a chemical-induced ACD murine model, we collected trigeminal ganglions of ACD and control mice for quantitative tandem mass tag (TMT)-labeling proteomic analysis. Immunohistochemistry was further practiced to validate the bioinformatic analysis. A total of 7685 proteins were identified and analyzed. Sixty-four proteins were significantly upregulated, and 75 proteins were downregulated in ACD mice. GO analysis demonstrated that the changed proteins were significantly enriched in terms of immune and peptidase activity in ACD mice. Proteins involved in the complement and coagulation cascades were notably changed in the KEGG enrichment analysis. The upregulation of complement component 3 (C3) in trigeminal satellite cells of ACD mice was further confirmed by immunohistochemistry. ACD upregulated C3 in trigeminal satellite cells. The complement system in sensory ganglion might play an essential role in forming pruritic and nociceptive sensations in ACD.

Background Methylisothiazolinone (MI) and Methylchloroisothiazolinone (MCI) are among the most common skin sensitizers, yet the immunological events that occur during MCI/MI allergic contact dermatitis (ACD) are still poorly understood. Objectives To analyse dendrocytes, macrophage subtypes and T cells in skin during the elicitation phase of MCI/MI ACD. Methods Thirteen patients with positive patch test reactions to MCI/MI (ACD group) and 11 individuals with negative patch test results were selected. Skin biopsies were only performed at 48 hours of patch testing. Immunohistochemistry was conducted to assess T cells, dendrocytes (Factor XIIIa), M1 (p-Stat1, CD68) and M2 (c-Maf, CD163) macrophages. Transcriptional analyses were performed for cytokines and related factors, and further compared to atopic dermatitis samples (n=4). Immunofluorescence assays addressed T cells location, along with IL-4 or IL-13, within the skin. Results MCI/MI elicited dermal dendrocytes and macrophages, pronouncedly the M2 subtype. T cells, majorly CD4+ T cells, accumulated in the perivascular areas. Similarly, abundant IL-4 protein was detected in these areas. There was an upregulation of IL-4 and IL-13 mRNA expression, a mild increase in IFNG mRNA levels and a down-regulation of RORC in the ACD group. Immunofluorescence revealed dermal clusters of T cells co-localized with IL-4. Conclusions M2 macrophages and Th2 cells participate in the immunopathogenesis of MCI/MI ACD. Dermal dendrocytes and M2 macrophages may assist the formation of CD4+ T cells perivascular clusters. These findings render a mechanistic insight into the MCI/MI reaction. Further analysis at different timepoints of patch testing is required to fully comprehend this ACD kinetics.

Interleukin-1β (IL-1β) is an important pro-inflammatory cytokine that has an effect on almost every cell lineage in the body. By blocking IL-1β and investigating the IL-1β signaling pathway, several studies have demonstrated a central role of IL-1β in the response to contact allergens. This review summarizes the current literature regarding the basic immunological mechanisms mediated by IL-1β in the different phases of allergic contact dermatitis (ACD) and highlights potential IL-1β-targeted treatment options, which in the future may be relevant in the treatment of patients with ACD. This review is primarily based on studies using various mouse models and human in vitro studies as clinical studies on the effect of IL-1β in ACD are lacking. This article is protected by copyright. All rights reserved.

Background Colophonium (rosin) can cause allergic contact dermatitis, mainly due to autoxidation of abietic acid (AbA). Products containing ≥0.1% colophonium should be labeled with EUH208 - "Contains rosin; colophony. May produce an allergic reaction." How should this be measured? Objective To compare the results from different strategies for estimating colophonium levels in consumer products: (a) from AbA, and (b) the sum of all major resin acids. To investigate the ratio of 7-oxodehydroabietic acid (7-O-DeA)/AbA as indication of autoxidation. Methods Resin acids were extracted from consumer products, derivatized, and then separated by gas chromatography/mass spectrometry (GC/MS). Results Resin acids were detected in 9 of 15 products. No product contained colophonium ≥0.1%. Estimation based on AbA resulted in underestimation of the colophonium levels in four of nine products. For three products, the obtained levels from this strategy were only one of two compared to when estimating from the sum of all resin acids. The ratio 7-O-DeA/AbA varied from 74% to 1.4%. Conclusions We propose to measure colophonium based on the sum of all detectable major resin acids, including 7-O-DeA. The ratio of 7-O-DeA/AbA should be used as a marker of autoxidation, indicating an increased risk of sensitization. The presented analytical method is simple to use and suitable for further screening studies.

Background Limited data exists on occupational allergic contact dermatitis (OACD) in Turkey. Objectives To investigate the epidemiologic profile of OACD in Turkey. Methods A retrospective cohort study on 294 patients with OACD among 2801 consecutively patch-tested patients in the allergy unit of the dermatology department of Istanbul Faculty of Medicine between 1996-2019. Results The overall prevalence of OACD was 10.5%, showing a male predominance. OACD was most frequently seen in construction workers (45.2%), followed by hairdressers, metalworkers, healthcare workers, and miscellaneous. The main relevant allergens were chromium in cement, thiurams in rubber gloves, hairdressing chemicals, resins/glues/plastics, metals, isothiazolinones, and fragrances. Hands were the mainly involved site (95.6%). Airborne eczema was observed in 21.4%. Hand&foot eczema and co-sensitizations to chrome&thiuram and chrome&cobalt were significantly associated with being a construction worker. Sensitizations to isothiazolinones in house painters, ammonium persulfate and p-phenylenediamine in hairdressers, and colophonium increased after 2010. Conclusion These were the largest data on OACD from Turkey, reflecting the importance of rubber glove allergy in all occupations and the striking increase in ammonium persulfate allergy among hairdressers. Chrome and cobalt were still the main cement allergens in Turkey, where the cement directive is not yet in force. This article is protected by copyright. All rights reserved.

Systemic contact dermatitis (SCD) is a generalized reactivation of type IV hypersensitivity skin diseases in individuals with previous sensitization after a contact allergen is administered systemically. Patients with SCD may consider their dermatitis unpredictable and recalcitrant since the causative allergens are difficult to find. If a patient has a pattern of dermatitis suggestive of SCD but fails to improve with conventional treatment, SCD should be taken into consideration. If doctors are not familiar with the presentations of SCD and the possible routes of allergen sensitization and exposure, the diagnosis of SCD may be delayed. In this work, we summarized all of the routes through which allergens can enter the body and cause SCD, including oral intake, local contact (through skin, inhalation, nasal spray and anal application), implants, and other iatrogenic or invasive routes (intravenous, intramuscular, intraarticular, and intravesicular). This will provide a comprehensive reference for the clinicians to identify the culprit of SCD.

Dermatitis encompasses a spectrum of inflammatory skin disorders with aberrant immune responses classified as type 1, type 2, and/or type 3. Major advances in the understanding of the pathogenesis of atopic dermatitis (AD) have shed new light on how innate immune responses critically regulate type 2 inflammation and itch. This article highlights the diverse ways by which type 2 immune cells regulate diseases beyond AD. The discovery of human Mas-related G protein-coupled receptor X2 on mast cells has revealed novel T cell-independent and immunoglobulin E-independent mechanisms of allergic contact dermatitis-associated and urticarial itch, respectively.

Allergic contact dermatitis (ACD) affects up to 20% of adults and children, although children are infrequently patch tested. Available data suggest that children and adults, with or without atopic dermatitis, have the same prevalence of ACD. Patch testing is the gold standard for evaluation of ACD. The Pediatric Baseline Series was recently published by expert consensus for use in pediatric patch testing, with additional allergens tested as guided by history. This article examines methods of patch testing and up-to-date data on pediatric ACD. The top allergens are reviewed, and avoidance strategies are discussed.

Occupational contact dermatitis is the most common occupational skin disease (OSD), and most of them are irritant in nature. There is less information available about contact urticaria than contact dermatitis. There are several strategies to prevent OSD, although workplace studies suggest there are gaps in their use in the workplace. Because early detection leads to improved outcomes, screening for dermatitis in industries such as health care would be useful. Both diagnosis and management involve 2 components: the actual disease diagnosis and medical treatment and the work-relatedness and management of the workplace to reduce exposures.

BACKGROUND Patch testing is the gold standard diagnostic test for allergic contact dermatitis and needs to be relevant to the region and the population being tested. The aim of this study was to develop a specific New Zealand baseline series (NZBS). METHOD We performed a retrospective case note review of patients attending four regional patch test centres between 2008 and 2020. Demographic and diagnostic information was collected for each patient along with results of patch testing. Using the results of this review, a group of 11 dermatologists with an interest in contact dermatitis agreed on a core group of allergens for inclusion in an NZBS, based on the frequency of positive reactions and allergens of interest. The remaining potential allergens were ranked by each dermatologist using an online questionnaire, with inclusion in the final NZBS by consensus. RESULTS Results from 2402 patients (67% female, mean age 44 years) from Auckland, Wellington, Palmerston North and Christchurch were collated. The 10 most frequent positive (relevant and non-relevant) allergens were nickel sulfate (22.0%), fragrance mix I (8.6%), cobalt chloride (7.3%), Myroxylon pereirae (5.6%), colophonium (5.1%), p-phenylenediamine (4.9%), methylisothiazolinone/methylchloroisothiazolinone (4.1%), fragrance mix II (3.9%), potassium dichromate (3.5%) and methylisothiazolinone (3.4%). Based on these results, a core series of 30 allergens was developed, with an additional 30 allergens added to form the extended series (total 60 allergens). CONCLUSION The baseline series of patch test allergens for routine use in New Zealand (NZBS) is based on national patch test data and expert consensus.

BACKGROUND In March 2014, the European Commission issued a new regulation restricting the content of hexavalent chromium (Cr) in leather to no more than 3 mg/kg. We previously performed a questionnaire study in January 2014 to characterize our patients with Cr contact allergy prior to regulatory intervention. OBJECTIVES To assess whether clinical characteristics, self-reported sources of Cr exposure, and burden of disease changed in patients with Cr allergy over time. METHODS A questionnaire study was performed among 172 adult dermatitis patients with Cr allergy and 587 age- and sex-matched dermatitis patients without Cr allergy. A questionnaire was sent to all dermatitis patients patch tested from 2003 to 2018 in August 2019. RESULTS The overall response rate was 61.2% (759/1241). Patients with Cr allergy were still more commonly affected by current foot dermatitis (odds ratio [OR] 3.82, 95% confidence interval [CI] 2.07-7.08) and hand dermatitis (OR 1.98, 95% CI 1.13-3.49) compared with controls diagnosed during 2013 to 2018. The proportion of patients with Cr allergy reporting dermatitis caused by leather exposure did not change during 2003 to 2012 vs 2013 to 2018 (71.0% vs 66.2%, P = .5). Furthermore, estimates on occupational performance and disease severity (eg, current dermatitis), number of anatomical locations with dermatitis, worst-case dermatitis, and effect on work were similar in patients with Cr allergy for 2003 to 2012 vs 2013 to 2018. CONCLUSION No immediate sign of improvement was found in patients with Cr allergy concerning severity of disease and dermatitis from leather exposures 5 years after adoption of the regulation against hexavalent Cr in leather. The regulation may have to be revised for better protection of those already sensitized.

Patch test reactions during dupilumab treatment showed a reproducibility rate of 29%. Reproducibility rates were higher for initially extreme (+++) or strong positive (++) reactions. Patch test reactions might be suppressed during dupilumab treatment, possibly leading to false negative reactions.

Objective To provide an approach to identifying topical medicament ingredients that cause allergic contact dermatitis (ACD) and to recognizing common clinical scenarios in which these ingredients might present. Sources of information A retrospective chart review was conducted of patients patch tested at the Contact Dermatitis Clinic at St Paul’s Hospital in Vancouver, BC, between November 2016 and June 2019. Data from the North American Contact Dermatitis Group from 2015 to 2016 and The Ottawa Hospital patch test clinic from 2000 to 2010 were also reviewed. Main message Topical antibiotics are the most common cause of ACD to medicaments and frequently cause cosensitization to multiple allergens. This hypersensitivity reaction is often seen following surgical procedures and should be distinguished from postoperative infection. Corticosteroid allergy is easy to miss and should be suspected in cases of corticosteroid-sensitive dermatoses that worsen despite appropriate treatment. Topical anesthetics and propylene glycol are other causes of ACD found in many prescription and over-the-counter products. Conclusion Allergic contact dermatitis is easy to miss and should always be considered in cases of eczematous eruptions. A thorough drug history including all topical products—both prescription and over-the-counter—is critical. Patch testing can help identify specific allergens for the patient to avoid.

Background In a European study on contact allergy in the general population, it has been hypothesized that the combination of contact allergy to a fragrance together with a history indicating dermatitis at exposure and thereafter subsequent avoidance of scented products implied a diagnosis of allergic contact dermatitis.Objectives The primary aim of this study was to validate this hypothesis/algorithm. The secondary aim was to investigate whether there was any association between the outcome of the recent repeated open application test (ROAT) and the patch test reactivity.Methods One hundred nine subjects with and without contact allergy to fragrance mix II (FM II) were recruited. Volunteers from six European dermatology clinics participated in the study including a patch test and a ROAT.Results Twenty-four positive ROAT reactions were noted in total including 20 of those 32 with contact allergy to FM II. None of the volunteers reacted to the vehicle (P < 0.001). More individuals with a positive algorithm had positive ROATs when compared with those with a negative algorithm. However, the difference was not statistically significant (P = 0.12). The lower the patch test concentration eliciting a positive test reaction, the more likely was a positive ROAT and the more likely that the positive ROAT appeared early during the investigative period.Conclusions The algorithm used in this study was not validated but it was indicated in this ROAT setup. The stronger the patch test reactivity the more likely was a positive ROAT and the more likely it was that the positive ROAT appeared early during the application period.

Background Because Myroxylon pereirae (MP), or balsam of Peru, is nowadays almost not used “as such,” and fragrance mix 1 (FM1) apparently is more sensitive in detecting fragrance allergy, the usefulness of testing MP in baseline series was recently questioned. Objectives Identification of the number of clinically relevant patch test reactions to MP not detected by FM1. Methods Retrospective analysis of 12 030 patients patch tested with MP and FM1 for contact dermatitis between January 2018 and December 2019 in 13 Italian dermatology clinics. Results Four hundred thirty‐nine patients (3.6%) had a positive patch test reaction to MP; 437 (3.6%) had a positive patch test reaction to FM1. Positive reactions to both MP and FM1 were observed in 119 subjects (1.0%), 310 (2.6%) reacted to MP only, 304 (2.5%) to FM1 only, 5 to MP and sorbitan sesquioleate (SSO), 9 to FM1 and SSO, and 5 to MP, FM1, and SSO. Single sensitizations were clinically relevant in 75.2% of cases for MP (62.9% current, 12.3% past) and 76.3% for FM1 (70.1% current, 6.2% past). Conclusions Based on our results, MP appears to be still worth testing along with FM1 in baseline series, because it allows detection of a remarkable number of fragrance allergies, often relevant, which would be otherwise missed.

Background: Patch test (PT) reactions to thiuram mix (TM) and fragrance mix (FM) I or II without concomitant reactions to their single constituents are potentially caused by the irritant properties of the mixes. Objective: Comparing inflammatory profiles of PT reactions to TM, FM I, FM II, and their constituents and assessing their potential in discrimination of irritant and allergic reactions. Patients and Methods: Levels of 14 cytokines and natural moisturizing factor (NMF) were determined in stratum corneum samples collected from PT reactions to TM, FM I or II, their constituents, and petrolatum (pet.) control sites in 36 individuals. Results: Levels of interleukin (IL)-16, chemokine (CXC motif) ligand (CXCL) 8, CXCL10, chemokine (CC motif) ligand (CCL) 17, and CCL22 were significantly increased in reactions (+, ++) to thiurams and fragrances compared to their petrolatum. controls, except for PT reactions to FM I/II with negative breakdown testing in which, however, decreased levels of NMF were observed. In doubtful reactions to FM I/II with negative breakdown testing, NMF was significantly lower than in petrolatum controls. Conclusions: PT reactions to thiurams and fragrances indicate a Th2-skewed inflammation. The inflammatory profiles suggest that weak or doubtful FM I/II reactions without accompanying reaction to a constituent were irritant. IL-16 might be suitable to distinguish irritant from allergic reaction.

Patch testing, used in the assessment of allergic contact dermatitis, is ideally avoided in patients receiving immunosuppressive therapy because of concerns with reductions in accuracy; however, this is not well characterized in the literature. This systematic review summarizes patch testing results in patients receiving immunosuppressive therapy. We identified 16 studies, comprising 195 patients with dermatitis or psoriasis, who were patch tested while receiving immunosuppressants. Of these, 7 studies, comprising 85 patients with dermatitis, patch tests were performed before and during immunosuppression. Overall, 67.9% (n = 19) of the dermatitis patients receiving dupilumab maintained positive reactions to an allergen that previously graded as a 2+/3+ reaction. Several immunosuppressants were also associated with positive patch test results for various allergens. These include dupilumab, cyclosporine, and low-dose prednisone (≤10 mg/d) for dermatitis, and tumor necrosis factor α inhibitors, ustekinumab, and methotrexate for psoriasis. Ideally, it is preferable to patch test when patients are not receiving oral immunosuppressants or immunomodulators. However, clinicians may choose to assess the risks and benefits of patch testing for each patient given the impact of allergic contact dermatitis on patient quality of life.

Background: The reliability of patch testing with expired Indian standard patch test kits has been not evaluated before. Methods: Thirty adults (men:women 25:5) with allergic contact dermatitis were divided into three groups of ten patients each for patch testing by Finn chamber® method using Indian standard patch test kits having expiry in 2016, 2015 and 2014. The results were compared with those from a new kit with 2018 expiry. Results: Ten patients in group-1, eight patients in group-2 and seven patients in group-3 developed positive reactions of identical intensities and mostly from identical allergens from all four kits. The major contact allergens eliciting positive reactions of identical intensities were parthenium in nine, five and three patients, colophony in four, one and zero patients, fragrance mix in three, three and one patients, thiuram mix in three, one and one patients, and paraphenylene diamine in two, one and three patients from group-1,-2, and -3, respectively. Limitations: Small number of patients in each group remains the major limitation of the study. Whether or not these results can be extrapolated with patch test results from other similar patch test kits available across countries also needs confirmation. Conclusion: The patch test allergens can be used beyond labeled expiry dates but needs confirmation by a few large studies and using other available patch test kits. This is important as the relevance of patch test results for individual allergen in this scenario may remain debatable requiring careful interpretation.

Eyelid dermatitis is a common dermatologic complaint.To characterize patients with eyelid dermatitis.Retrospective analysis (1994-2016) of North American Contact Dermatitis Group data.Of 50,795 patients, 2332 (4.6%) had eyelid dermatitis only, whereas 1623 (3.2%) also had dermatitis of the eyelids and head or neck. Compared with patients without eyelid involvement (n = 26,130), groups with eyelid dermatitis only and dermatitis of the eyelid and head or neck were significantly more likely to be female, white, and older than 40 years, and to have a history of hay fever, atopic dermatitis, or both (P .01). Final primary diagnoses included allergic contact dermatitis (eyelid dermatitis only: 43.4%; dermatitis of the eyelid and head or neck: 53.5%), irritant contact dermatitis (eyelid dermatitis only: 17.0%; dermatitis of the eyelid and head or neck: 9.8%), and atopic dermatitis (eyelid dermatitis only: 13.1%; dermatitis of the eyelid and head or neck: 13.8%). Top 5 currently relevant allergens included nickel sulfate (eyelid dermatitis only: 18.6%; dermatitis of the eyelid and head or neck: 22.5%), fragrance mix I (eyelid dermatitis only: 16.5%; dermatitis of the eyelid and head or neck: 18.3%), methylisothiazolinone (eyelid dermatitis only: 16.5%; dermatitis of the eyelid and head or neck: 17.7%), gold sodium thiosulfate (eyelid dermatitis only: 14.7%; dermatitis of the eyelid and head or neck: 11.4%), and balsam of Peru (eyelid dermatitis only: 11.9%; dermatitis of the eyelid and head or neck: 12.6%). Both eyelid-involvement groups were significantly more likely to react to gold sodium thiosulfate, carmine, shellac, dimethylaminopropylamine, oleamidopropyl dimethylamine, and thimerosal (P .05) compared with the no eyelid involvement group.Lack of specific distribution patterns of eyelid dermatitis and no long-term follow-up data.Patch testing remains a critical tool in evaluating patients with eyelid dermatitis.

The food industry is a high-risk area for work-related allergic immediate skin reactions (contact urticaria, contact urticaria syndrome, protein contact dermatitis) with or without respiratory symptoms (allergic rhinitis, allergic asthma) due to proteins of animal origin.The present work gives an overview of allergenic seafood and meat proteins and their clinical and occupational relevance in different work settings.A review of current knowledge and a supplementary selective literature search were performed.Protein contact dermatitis is one of the more common occupational dermatoses in workers exposed to seafood and meat, after irritant hand eczema. Fishermen, cooks, and butchers are most commonly affected. Crustaceans and mollusks are more frequent triggers of food allergies than fish and can in individual cases also be life threatening. In contrast, primary meat allergy is rare. Beef among mammals and chicken among birds are the most common triggers.All employees with allergic immediate skin and/or respiratory reactions exposed to proteins of animal origin in the workplace should undergo a careful allergological workup at an early stage. Determination of the specific IgE plays a central role in confirming the diagnosis and it is of great importance in individual cases to include the suspected native material in the skin tests. The course of the disease is generally characterized by a poor prognosis and is commonly associated with a change in occupation.HINTERGRUND: Die Nahrungsmittelwirtschaft zählt zu den Hochrisikobereichen für arbeitsbedingte allergische Sofortreaktionen an der Haut (Kontakturtikaria, Kontakturtikariasyndrom, Proteinkontaktdermatitis) mit oder ohne respiratorische Symptome (allergische Rhinitis, allergisches Asthma) durch Proteine tierischen Ursprungs.Die vorliegende Arbeit gibt einen Überblick über allergene Meerestier- und Fleischproteine und deren klinische und beruflich Relevanz in verschiedenen Tätigkeitsbereichen.Es erfolgten die Aufbereitung von aktuellem Wissen sowie eine ergänzende selektive Literaturrecherche.Nach dem irritativen Handekzem ist die Proteinkontaktdermatitis eine häufige Berufsdermatose unter Beschäftigten mit Kontakt zu Meerestieren und Fleisch. Fischer, Köche und Metzger sind an erster Stelle betroffen. Noch vor den Fischen zählen Krusten- und Weichtiere zu den häufigsten Auslösern von in Einzelfällen auch vital bedrohlichen Nahrungsmittelallergien. Demgegenüber ist eine primäre Fleischallergie selten. Rindfleisch unter den Säugetieren und Hühnerfleisch unter den Vögeln sind die häufigsten Auslöser.Bei allen Beschäftigten mit allergischen Sofortreaktionen an der Haut und/oder den Atemwegen, die gegenüber Proteinen tierischen Ursprungs am Arbeitsplatz exponiert sind, sollte frühzeitig eine sorgfältige allergologische Abklärung durchgeführt werden. Spielt heute die spezifische Ig(Immunglobulin)E-Bestimmung bei der Diagnosesicherung eine zentrale Rolle, wird es in Einzelfällen von großer Bedeutung sein, das angeschuldigte Nativmaterial in die Hauttestungen einzubeziehen. Die Krankheitsverläufe sind allgemein durch eine schlechte Prognose und häufige Berufswechsel charakterisiert.

Background Hand eczema (HE) is a heterogeneous and burdensome disorder. Objective To characterize the clinical characteristics, etiologies and allergen relevance in adults with HE referred for patch testing. Methods Retrospective analysis (2000-2016) of North American Contact Dermatitis Group data (n = 37,113). Results Overall, 10,034 patients had HE, with differences of overlap between allergic contact, irritant contact, and atopic dermatitis. Allergic contact HE fluctuated, whereas atopic HE steadily increased, and irritant HE decreased over time. HE was associated with higher proportions of positive patch tests (67.5% vs 63.8%; χ2, P Limitations No data on HE phenotype. Conclusion HE in adults was associated with higher proportions of positive patch tests, with a heterogeneous profile of allergens. Patch testing remains an important tool in the evaluation of patients with HE.

Background Scalp conditions are often multifactorial. Objective To characterize patients with scalp involvement and patch-testing outcomes. Methods Retrospective cross-sectional analysis of North American Contact Dermatitis Group data (1996-2016). Study groups included patients with scalp involvement (≤3 anatomic sites coded) with or without additional sites. Results A total of 4.8% of patients (2331/48,753) had scalp identified as 1 of up to 3 affected anatomic sites. Approximately one-third of "scalp-only" individuals had a specific primary diagnosis of allergic contact dermatitis (38.6%), followed by seborrheic dermatitis (17.2%) and irritant contact dermatitis (9.3%). When adjacent anatomic sites were affected, allergic contact dermatitis was more frequently identified as the primary diagnosis (>50%). The top 5 currently clinically relevant allergens in scalp-only patients were p-phenylenediamine, fragrance mix I, nickel sulfate, balsam of Peru, and cinnamic aldehyde. Methylisothiazolinone sensitivity was notable when adjacent anatomic sites were involved. The top 3 specifically identified sources for scalp-only allergens were hair dyes, shampoo/conditioners, and consumer items (eg, hair appliances, glasses). Limitations Tertiary referral population. Conclusion Isolated scalp involvement was less likely to be associated with allergic contact dermatitis than when adjacent anatomic sites were involved. Overlap with multiple diagnoses was frequent, including seborrheic dermatitis, irritant dermatitis, other dermatoses, or all 3. p-Phenylenediamine was the most common allergen.

Background Patch testing with the European Baseline Series (EBS) is an essential diagnostic tool for the assessment of allergic contact dermatitis. Objective The aims of the study were to describe the most common contact allergens identified with patch testing in Turkey and to establish the distribution of contact allergens among different regions in Turkey. Patients and methods Twelve centers consisting of tertiary health care institutions were included in the study. A total of 1169 patients were patch tested with the EBS from 2015 to 2017. Results A total of 596 patients (51.0%) had 1 or more positive patch test reactions to the EBS. A total of 30.2% (n = 353) of those tested had clinical relevance. Contact sensitivity was more common in young patients. The most common 10 allergens were nickel sulfate (20.4%), followed by textile dye mix (8.6%), cobalt chloride (8.3%), potassium dichromate (8.0%), p-phenylenediamine base (4.5%), balsam of Peru (4.3%), methylchloroisothiazolinone/methylisothiazolinone (3.8%), thiuram mix (3.6%), fragrance mix I (3.0%), and methylisothiazolinone (2.9%). Conclusions This study provides a comprehensive profile of patch test results with the EBS in Turkey. An ongoing decrease in contact allergy to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone was observed. Textile dye mix and p-phenylenediamine are beginning to pose a new risk in Turkey.

Background Few studies examined the relationship between nummular (discoid) eczema (NE) and allergic contact dermatitis (ACD). Objective To examine the trends, associations, and clinical relevance of ACD in NE patients referred for patch testing. Methods Retrospective analysis of 38,723 patients from the North American Contact Dermatitis Group. Results Overall, 748 (1.9%) patients were diagnosed with NE; 23.9% had a concomitant diagnosis of ACD. The prevalence of NE fluctuated over time between 2001-2016, with no overall change in prevalence in diagnosed NE. In multivariable logistic regression models, NE steadily increased with age and was associated with male sex, Asian and other race/ethnicity, and inversely associated with a history of AD and hay fever. Patients with NE had lower proportions of ≥1 positive allergic reaction and lower odds of a positive reaction in multiple, individual allergens. The most commonly relevant allergens in patients with NE were formaldehyde 2.0% aq., methylisothiazolinone, quaternium-15, fragrance mix I, and propylene glycol. Conclusion NE is a heterogeneous disorder with distinct subsets of lesional distribution and profile of relevant allergens, especially formaldehyde and formaldehyde releasers. Nearly 1 in 4 NE patients had ACD, supporting the role of patch testing in NE patients. This article is protected by copyright. All rights reserved.

IL-1 functions as an essential pro-inflammatory mediator for the sensitisation of allergic contact dermatitis (ACD). However, studies conducted to date have typically used a limited number of haptens and examined their effects only on murine ACD or murine dendritic cells (DCs). It therefore remains unclear whether IL-1α and/or IL-1β is produced in ACD induced by haptens other than those commonly used in mouse ACD models, and whether they are essential for sensitisation leading to ACD in humans. In addition, it is unclear whether human DCs also produce IL-1α or IL-1β after stimulation by haptens in general. Here, we first demonstrated that 10 haptens (3 extreme, 1 strong, 3 moderate and 3 weak) increased both IL-1α mRNA and IL-1β mRNA expression by the human monocyte cell line THP-1, a commonly used surrogate of DCs in in vitro skin sensitisation tests. Next, we constructed an in vitro skin sensitisation test using a stable IL-1β reporter cell line, THP-G1b, and evaluated whether 88 haptens and 34 non-haptens increase IL-1β reporter activity. We found that 94% of 77 haptens evaluated after considering their applicability domain and solubility in the chosen media stimulated reporter activity. These studies demonstrated that most haptens, irrespective of their potency, increased IL-1β mRNA expression by THP-1 cells, confirming that human DCs also produce IL-1β after stimulation by most haptens. The luciferase assay using THP-G1b cells is thus another skin sensitisation test based on the adverse outcome pathway with reasonable performance.

BACKGROUND: Phenol-formaldehyde resin 2 (PFR2) has been shown to be a useful marker of contact allergy (CA) to various phenol-formaldehyde resins. These compounds are used in various industries as solids, powders or semisolid resins and are known to be sensitising agents. OBJECTIVES: The aims were to investigate the contact allergy to PFR2 in a single tertiary dermatology centre, to investigate associated simultaneous allergic reactions, and to identify cases of allergic contact dermatitis (ACD) to PFR2. METHODS: A retrospective study was performed of patients patch tested to PFR2 between January 1, 2003 and June 17, 2020. RESULTS: Some 337 of 7922 patients were tested to PFR2 and 16 (4.7%) reacted. Of those 16 individuals, 6 (37.5%) had a relevant reaction (1.8% of total). Simultaneous allergic reactions were noted to colophonium in 8 (50.0%), Myroxylon pereirae in 5 (31.3%), and fragrance mix 1 in 4 cases (25.0%). CONCLUSION: Contact allergy to PFR2, even in a selected population of patients, is uncommon. However, patients exposed to plastic and glues, or who work with wood products should be routinely patch tested to a plastics and glues series containing PFR2. We recommend that all centres include PFR2 in their plastics and glues series. This article is protected by copyright. All rights reserved.

Environmental light levels can affect physiological functions, such as general activity, body temperature and metabolism. Irregular lifestyles, such as those involving exposure to light during the night, can exacerbate the clinical symptoms of several inflammatory skin diseases. However, the effects of constant light exposure on immune responses are not fully understood. This study aimed to elucidate the effects of constant light exposure on two major types of skin reactions, allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD). BALB/c mice were kept under constant light conditions or a normal light and dark cycle, and their ACD and ICD responses were assessed after the topical application of 2,4,6-trinitro-1-chlorobenzene and croton oil, respectively, to the ear skin. Interestingly, in both ACD and ICD, the ear-swelling response and local leukocyte infiltration were aggravated by constant exposure to light, which has previously been shown to severely disturb the behavioural rhythms of mice. In ACD, these findings were accompanied by increases in the numbers of degranulated mast cells and eosinophils. These results suggest that constant light exposure intensifies allergic and non-allergic skin inflammation.

Background The common contact allergens may change over time as the environmental exposure changes. Objectives To identify the prevalence rates and changing trends of contact allergens in Taiwan over a 40-year period. Materials & methods The patch testing results of a referral centre from 1978 to 2018 were retrospectively reviewed. The study population was divided into four groups according to 10-year intervals. The prevalence rates of contact sensitization to each agent and the clinical relevance were analysed. For patients with positive reactions to relevant allergens, the occupations and sites of dermatitis were analysed. Results From 1978 to 2018, a total of 4005 patients underwent patch testing. Successively increasing trends of positive reactions to cobalt, fragrance mix I, and para-phenylenediamine (PPD) were found. Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) was an emerging contact allergen. Hairdressers, cosmetologists, and aromatherapists became the occupations most commonly having positive reactions in the most recent 10 years. In the first two decades, the face and neck were the most commonly affected areas. Later, hands became the most commonly affected sites. Conclusions The prevalence rates of positive reactions to cobalt, fragrance mix I, and PPD increased successively. MCI/MI was an emerging contact allergen of special concern.

Background: Our previous findings demonstrated that in vitro supplementation of polyphenols, extracted from seeds of red grape (Nero di Troia cultivar), to peripheral lymphomonocytes from patients affected by allergic contact dermatitis (ACD) to nickel (Ni) could reduce the release of proinflammatory cytokines and nitric oxide (NO), while increasing the levels of interleukin (IL)-10, an anti-inflammatory cytokine. Objective: To assess whether an intervention with oral administration of polyphenols leads to a reduction of peripheral biomarkers in ACD patients. Methods: At T0, 25 patients affected by ACD to Ni were orally administered with 300 mg polyphenols prodie extracted from seeds of red grape (Nero di Troia cultivar) (NATUR-OX®) for 3 months (T1). The other 25 patients affected by ACD to Ni received placebo only for the same period of time. Serum biomarkers were analyzed at T0 and T1. In both groups, seven dropouts were recorded. Result: At T1 in comparison to T0, in treated patients, values of interferon-γ, IL-4, IL-17, pentraxin 3 and NO decreased, while IL-10 levels increased when compared with T0 values. Conversely, in placebo- treated patients, no modifications of biomarkers were evaluated at T1. Conclusion: Present laboratory data rely on the anti-oxidant, anti-inflammatory and anti-allergic properties of polyphenols.

Patch testing is the criterion standard for diagnosing allergic contact dermatitis. Causative allergens differ between children and adults, necessitating the development of pediatric-specific patch test series. The Pediatric Baseline Series was developed in 2018 through expert consensus and includes relevant pediatric allergens that dermatologists can use in practice. Obstacles in patch testing, such as the need for multiple office visits, length of patch application, and avoidance of sweat and water on the testing area, are particularly challenging for the pediatric population, and several strategies are proposed. Aside from formal patch testing, alternatives like the repeat open application test and empiric allergen avoidance can be helpful in children. The key to management of allergic contact dermatitis is allergen avoidance, with emphasis on the need to properly identify causative allergens. Continued data collection through registries allows for a better understanding of the diagnosis and management of pediatric allergic contact dermatitis.