Leukotriene receptor antagonists as add-on therapy to antihistamines for urticaria: a systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: The benefits and harms of adding antileukotrienes to H1-antihistamines for the management of urticaria (hives, itch, and/or angioedema) remain unclear. OBJECTIVE: We sought to systematically synthesize the treatment outcomes of antileukotrienes in combination with H1-antihistamines versus H1-antihistamines alone for acute and chronic urticaria. METHODS: As part of updating American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma, and Immunology Joint Task Force on Practice Parameters urticaria guidelines, we searched MEDLINE, Embase, CENTRAL, LILACS, WPRIM, IBECS, ICTRP, CBM, CNKI, VIP, Wanfang, FDA, and EMA databases from inception to December 18th, 2023 for randomized controlled trials (RCTs) evaluating antileukotrienes and H1-antihistamines versus H1-antihistamines alone in patients with urticaria. Paired reviewers independently screened citations, extracted data, and assessed risk of bias. Random effects models pooled effect estimates for urticaria activity, itch, wheal, sleep, quality of life, and harms. The GRADE approach informed certainty of evidence ratings. Open Science Framework registration: https://osf.io/h2bfx/. RESULTS: Thirty-four RCTs enrolled 3,324 children and adults. Compared to H1-antihistamines alone, the combination of a leukotriene receptor antagonist (LTRA) with H1-antihistamines probably modestly reduces urticaria activity (mean difference: -5.04, 95%CI -6.36 to -3.71; 7-day Urticaria Activity Score) with moderate certainty. We made similar findings for itch and wheal severity, and quality of life. Adverse events were probably not different between groups (moderate certainty), however, no RCT reported on neuropsychiatric adverse events. CONCLUSION: Among patients with urticaria, adding LTRAs to H1-antihistamines probably modestly improves urticaria activity with little to no increase in overall adverse events. The added risk of neuropsychiatric adverse events in this population with LTRAs is small and uncertain.

Atopic Dermatitis and IgE-Mediated Food Allergy: Common Biologic Targets for Therapy and Prevention.

OBJECTIVE: To highlight common mechanistic targets for the treatment of atopic dermatitis (AD) and IgE-mediated food allergy (IgE-FA) with potential to be effective for both diseases and prevent atopic progression. DATA SOURCES: PubMed searches or NCT-registered clinical trials related to AD, IgE-FA, and other atopic conditions, especially focused on the pediatric population. STUDY SELECTIONS: Human seminal studies and/or articles published in the past decade were emphasized with reference to pre-clinical models when relevant. NCT-registered clinical trials were filtered by inclusion of pediatric subjects <18-years of age with special focus on children <12-years as a critical period when AD and IgE-FA diseases may often be concurrent. RESULTS: AD and IgE-FA share several pathophysiologic features, including epithelial barrier dysfunction, innate and adaptive immune abnormalities, and microbial dysbiosis, which may be critical for the clinical progression between these diseases. Revolutionary advances in targeted biologic therapies have demonstrated the benefit of inhibiting type 2 immune responses, using dupilumab (anti-IL-4Rα) or omalizumab (anti-IgE), to potentially reduce symptom burden for both diseases in pediatric populations. While the potential for biologics to promote disease remission (AD) or sustained unresponsiveness (IgE-FA) remains unclear, the refinement of biomarkers to predict infants at risk for atopic disorders provides promise for prevention through timely intervention. CONCLUSION: AD and IgE-FA exhibit common features that may be leveraged to develop biologic therapeutic strategies to treat both conditions and even prevent atopic progression. Future studies should be designed with consistent age-stratification in the pediatric population and standardized regimens of adjuvant oral immunotherapy or dose-escalation (IgE-FA) to improve cross-study interpretation.

Topical corticosteroids for hives and itch (urticaria): systematic review and Bayesian meta-analysis of randomized trials.

BACKGROUND: Topical corticosteroids are widely used as a treatment for itch and wheals (urticaria), but their benefits and harms are unclear. OBJECTIVE: To systematically synthesize the benefits and harms of topical corticosteroids for the treatment of urticaria. METHODS: We searched MEDLINE, EMBASE, and CENTRAL from database inception to March 23, 2024, for randomized trials addressing comparing topical corticosteroid to placebo for patients with urticaria (either chronic spontaneous or inducible urticaria or acute urticaria elicited from skin/intradermal allergy testing). Paired reviewers independently screened records, extracted data, and assessed risk of bias. Random-effects meta-analyses addressed urticaria severity, itch severity (numeric rating scale; range 0-10; higher is worse), and adverse events. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach informed certainty of evidence ratings. PROSPERO registration: CRD42023455182. RESULTS: Nineteen RCTs enrolled 379 participants with a median of mean age of 30.1 years (range 21.1 to 44.0). Compared to placebo, topical corticosteroids may reduce wheal size (ratio of means 0.47, 95%CI 0.38 to 0.59; low certainty) and itch severity (mean difference -1.30, 95%CI -5.07 to 2.46; very low certainty). Topical corticosteroids result in little to no difference in overall adverse events (94 fewer patients per 1000, 95%CrI 172 fewer to 12 more; high certainty). CONCLUSION: Compared to placebo, topical corticosteroids may result in a reduction of wheal size, and result in little to no difference in overall adverse events. Topical corticosteroids may reduce itch severity, but the evidence is very uncertain. Future large, randomized trials addressing the use of topical corticosteroids would further support optimal urticaria management.

Role of Iodine-Assisted Aerosol Particle Formation in Antarctica.

New particle formation via the ion-mediated sulfuric acid and ammonia molecular clustering mechanism remains the most widely observed and experimentally verified pathway. Recent laboratory and molecular level observations indicate iodine-driven nucleation as a potentially important source of new particles, especially in coastal areas. In this study, we assess the role of iodine species in particle formation using the best available molecular thermochemistry data and coupled to a detailed 1-d column model which is run along air mass trajectories over the Southern Ocean and the coast of Antarctica. In the air masses traversing the open ocean, ion-mediated SA-NH3 clustering appears insufficient to explain the observed particle size distribution, wherein the simulated Aitken mode is lacking. Including the iodine-assisted particle formation improves the modeled Aitken mode representation with an increase in the number of freshly formed particles. This implies that more particles survive and grow to Aitken mode sizes via condensation of gaseous precursors and heterogeneous reactions. Under certain meteorological conditions, iodine-assisted particle formation can increase cloud condensation nuclei concentrations by 20%-100%.

Improved patient- and caregiver-reported outcomes distinguish tacrolimus 0.03% from crisaborole in children with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic skin disease that affects 20% of children worldwide and is associated with low patient-reported quality of life (QoL). Crisaborole (CRIS) and tacrolimus 0.03% (TAC) are Food and Drug Administration (FDA)-approved topical treatments for mild to moderate AD with similar clinical efficacy. Utilization of patient-reported outcomes (PROs) may provide meaningful data on the impact of AD treatments on patients and caregivers. This study used PROs to monitor the impact of crisaborole (CRIS) and tacrolimus 0.03% (TAC) on children with mild/moderate atopic dermatitis (AD) and caregiver burden. METHODS: This open-label study randomized 47 child-caregiver dyads to CRIS or TAC for 12 weeks. Disease severity, child quality of life (QoL), itch, pain interference, anxiety, depression, sleep, caregiver burden and caregiver QoL were assessed at baseline, 6 and 12 weeks. RESULTS: A total of 36 dyads completed the study. Children (mean age = 8.0 ± 3.9 years) had mild baseline AD and were diverse by race (39% white; 36% Black) and gender (53% males). Caregivers were mostly female (78%; mean age = 37 ± 7.6 years). Both arms improved disease severity (Eczema Area and Severity Index) from baseline to 12 weeks (CRIS = -2.4 vs. TAC = -1.9). Within-arm analyses comparing baseline to 12 weeks revealed TAC, but not CRIS, improved all child and caregiver PROs except sleep (all p < 0.05). CONCLUSIONS: Our results demonstrated that topical treatment for 12 weeks was more beneficial than 6 weeks, with TAC improving more PROs than CRIS. Future trials should implement PROs to fully understand the impact of AD treatments.

Direct field evidence of autocatalytic iodine release from atmospheric aerosol.

Reactive iodine plays a key role in determining the oxidation capacity, or cleansing capacity, of the atmosphere in addition to being implicated in the formation of new particles in the marine boundary layer. The postulation that heterogeneous cycling of reactive iodine on aerosols may significantly influence the lifetime of ozone in the troposphere not only remains poorly understood but also heretofore has never been observed or quantified in the field. Here, we report direct ambient observations of hypoiodous acid (HOI) and heterogeneous recycling of interhalogen product species (i.e., iodine monochloride [ICl] and iodine monobromide [IBr]) in a midlatitude coastal environment. Significant levels of ICl and IBr with mean daily maxima of 4.3 and 3.0 parts per trillion by volume (1-min average), respectively, have been observed throughout the campaign. We show that the heterogeneous reaction of HOI on marine aerosol and subsequent production of iodine interhalogens are much faster than previously thought. These results indicate that the fast formation of iodine interhalogens, together with their rapid photolysis, results in more efficient recycling of atomic iodine than currently considered in models. Photolysis of the observed ICl and IBr leads to a 32% increase in the daytime average of atomic iodine production rate, thereby enhancing the average daytime iodine-catalyzed ozone loss rate by 10 to 20%. Our findings provide direct field evidence that the autocatalytic mechanism of iodine release from marine aerosol is important in the atmosphere and can have significant impacts on atmospheric oxidation capacity.

Rapid reduction in Staphylococcus aureus in atopic dermatitis subjects following dupilumab treatment.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory disorder characterized by dominant type 2 inflammation leading to chronic pruritic skin lesions, allergic comorbidities, and Staphylococcus aureus skin colonization and infections. S aureus is thought to play a role in AD severity. OBJECTIVES: This study characterized the changes in the host-microbial interface in subjects with AD following type 2 blockade with dupilumab. METHODS: Participants (n = 71) with moderate-severe AD were enrolled in a randomized (dupilumab vs placebo; 2:1), double-blind study at Atopic Dermatitis Research Network centers. Bioassays were performed at multiple time points: S aureus and virulence factor quantification, 16s ribosomal RNA microbiome, serum biomarkers, skin transcriptomic analyses, and peripheral blood T-cell phenotyping. RESULTS: At baseline, 100% of participants were S aureus colonized on the skin surface. Dupilumab treatment resulted in significant reductions in S aureus after only 3 days (compared to placebo), which was 11 days before clinical improvement. Participants with the greatest S aureus reductions had the best clinical outcomes, and these reductions correlated with reductions in serum CCL17 and disease severity. Reductions (10-fold) in S aureus cytotoxins (day 7), perturbations in TH17-cell subsets (day 14), and increased expression of genes relevant for IL-17, neutrophil, and complement pathways (day 7) were also observed. CONCLUSIONS: Blockade of IL-4 and IL-13 signaling, very rapidly (day 3) reduces S aureus abundance in subjects with AD, and this reduction correlates with reductions in the type 2 biomarker, CCL17, and measures of AD severity (excluding itch). Immunoprofiling and/or transcriptomics suggest a role for TH17 cells, neutrophils, and complement activation as potential mechanisms to explain these findings.

The IL-4Rα Q576R polymorphism is associated with increased severity of atopic dermatitis and exaggerates allergic skin inflammation in mice.

BACKGROUND: Atopic dermatitis (AD) is characterized by TH2-dominated skin inflammation and systemic response to cutaneously encountered antigens. The TH2 cytokines IL-4 and IL-13 play a critical role in the pathogenesis of AD. The Q576->R576 polymorphism in the IL-4 receptor alpha (IL-4Rα) chain common to IL-4 and IL-13 receptors alters IL-4 signaling and is associated with asthma severity. OBJECTIVE: We sought to investigate whether the IL-4Rα R576 polymorphism is associated with AD severity and exaggerates allergic skin inflammation in mice. METHODS: Nighttime itching interfering with sleep, Rajka-Langeland, and Eczema Area and Severity Index scores were used to assess AD severity. Allergic skin inflammation following epicutaneous sensitization of mice 1 or 2 IL-4Rα R576 alleles (QR and RR) and IL-4Rα Q576 (QQ) controls was assessed by flow cytometric analysis of cells and quantitative RT-PCR analysis of cytokines in skin. RESULTS: The frequency of nighttime itching in 190 asthmatic inner-city children with AD, as well as Rajka-Langeland and Eczema Area and Severity Index scores in 1116 White patients with AD enrolled in the Atopic Dermatitis Research Network, was higher in subjects with the IL-4Rα R576 polymorphism compared with those without, with statistical significance for the Rajka-Langeland score. Following epicutaneous sensitization of mice with ovalbumin or house dust mite, skin infiltration by CD4+ cells and eosinophils, cutaneous expression of Il4 and Il13, transepidermal water loss, antigen-specific IgE antibody levels, and IL-13 secretion by antigen-stimulated splenocytes were significantly higher in RR and QR mice compared with QQ controls. Bone marrow radiation chimeras demonstrated that both hematopoietic cells and stromal cells contribute to the mutants' exaggerated allergic skin inflammation. CONCLUSIONS: The IL-4Rα R576 polymorphism predisposes to more severe AD and increases allergic skin inflammation in mice.

Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial.

BACKGROUND: Atopic dermatitis (AD) is characterized by microbial dysbiosis, immune dysregulation, and an impaired skin barrier. Microbial dysbiosis in AD involves a reduction in diversity primarily driven by an increased abundance of Staphylococcus aureus. Tralokinumab, an approved treatment for adults with moderate-to-severe AD, improves the skin barrier and immune abnormalities by specifically targeting the interleukin 13 cytokine, but its impact on the skin microbiome is unknown. OBJECTIVE: To investigate how tralokinumab affects the skin microbiome by examining the lesional skin of adults with moderate-to-severe AD from the phase 3 ECZTRA 1 trial (NCT03131648). METHODS: Microbiome profiling, S aureus abundance, and biomarker data were assessed in a subset of ECZTRA 1 participants (S aureus abundance at baseline and week 16; microbiome profiling at baseline, and week 8/16; and serum sampling before dose and week 4/8/16/28/52). RESULTS: Tralokinumab treatment led to increased microbial diversity, reduced S aureus abundance, and increased abundance of the commensal coagulase-negative Staphylococci. LIMITATIONS: Limitations include a lack of S aureus abundance data at week 8, sampling site variation between participants, and possible influence from concomitant systemic antiinfectives. CONCLUSION: Our findings indicate specific targeting of the interleukin 13 cytokine with tralokinumab can directly and/or indirectly improve microbial dysbiosis seen in AD skin.

Upadacitinib treatment withdrawal and retreatment in patients with moderate-to-severe atopic dermatitis: Results from a phase 2b, randomized, controlled trial.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by pruritic eczematous lesions. The effect of treatment withdrawal after response to upadacitinib oral treatment is not fully characterized. OBJECTIVES: Assess the effect of upadacitinib withdrawal on skin clearance and itch improvement in adult patients with moderate-to-severe AD and evaluate the kinetics of recovery on rescue treatment. METHODS: Data from a phase 2b randomized, placebo-controlled trial (NCT02925117) of upadacitinib in patients with moderate-to-severe AD were analysed. Patients were randomized 1:1:1:1 to receive upadacitinib 7.5 mg, 15 mg, 30 mg or placebo, and then at Week 16, patients were re-randomized 1:1 to receive the same dose of upadacitinib (upadacitinib 30 mg for patients initialized to placebo) or placebo. From Week 20, those who experienced loss of response defined as Eczema Area and Severity Index <50% improvement from baseline (EASI 50) received rescue treatment with upadacitinib 30 mg. RESULTS: Patients who withdrew from upadacitinib experienced a rapid loss of skin clearance response, while those who switched from placebo to upadacitinib gained response. Loss of skin clearance response occurred within 4 weeks and worsening of itch occurred within 5 days. In patients who originally received placebo or a lower dose of upadacitinib leading to a loss of EASI response, rescue treatment with upadacitinib 30 mg resulted in rapid recovery or improvement of both skin and itch responses; most patients who were re-randomized to placebo achieved EASI 75 and IGA 0/1 by 8 weeks of rescue treatment. No new safety risks were observed. CONCLUSIONS: Continuous treatment with upadacitinib is suggested to maintain skin clearance and antipruritic effects.

Abrocitinib efficacy and safety in patients with moderate-to-severe atopic dermatitis: Results from phase 3 studies, including the long-term extension JADE EXTEND study.

BACKGROUND: Abrocitinib improved signs and symptoms of moderate-to-severe atopic dermatitis (AD) at 12 or 16 weeks in phase 3 studies with a manageable safety profile. Further understanding of the abrocitinib long-term efficacy and safety profile is important for its appropriate use in treating chronic AD. OBJECTIVE: To evaluate the abrocitinib efficacy up to 48 weeks and long-term safety in patients with moderate-to-severe AD. METHODS: JADE EXTEND (NCT03422822) is an ongoing, phase 3, long-term extension study that enrolled patients from previous abrocitinib AD trials. This analysis focusses on patients from the phase 3 JADE MONO-1 (NCT03349060), JADE MONO-2 (NCT03575871) and JADE COMPARE (NCT03720470) studies who completed the full treatment period of placebo or abrocitinib (200 mg or 100 mg once daily) and subsequently entered JADE EXTEND. Efficacy endpoints included the proportion of patients achieving skin clearance (Investigator's Global Assessment [IGA] 0/1 [clear/almost clear]; ≥75% improvement in Eczema Area and Severity Index [EASI-75]) and itch response (Peak Pruritus Numerical Rating Scale [PP-NRS] severity ≥4-point improvement). Safety endpoints included treatment-emergent adverse events (TEAEs), serious TEAEs and TEAEs leading to discontinuation. Data cut-off: April 22, 2020. RESULTS: As of the data cut-off, ~70% and ~45% of patients received abrocitinib for ≥36 and ≥48 weeks, respectively. Nasopharyngitis, atopic dermatitis, nausea and upper respiratory tract infections were the most frequent TEAEs. Serious TEAEs occurred in 7% and 5% and TEAEs leading to study discontinuation occurred in 9% and 7% of patients receiving abrocitinib 200 mg and 100 mg, respectively. Week 48 efficacy responses with abrocitinib 200 mg and 100 mg were as follows: IGA 0/1 52% and 39%; EASI-75 82% and 67%, and PP-NRS severity ≥4-point improvement 68% and 51%. CONCLUSIONS: In patients with moderate-to-severe AD, long-term abrocitinib treatment resulted in clinically meaningful skin and pruritus improvement. The long-term safety profile was manageable and consistent with previous reports.

Signaling sphingolipids are biomarkers for atopic dermatitis prone to disseminated viral infections.

BACKGROUND: Life-threatening viral diseases such as eczema herpeticum (EH) and eczema vaccinatum (EV) occur in <5% of individuals with atopic dermatitis (AD). The diagnosis of AD, however, excludes all individuals with AD from smallpox vaccination. OBJECTIVES: We sought to identify circulatory and skin lipid biomarkers associated with EH and EV. METHODS: Stratum corneum and plasma samples from 15 subjects with AD and a history of EH, 13 age- and gender-matched subjects with AD and without EH history, and 13 healthy nonatopic (NA) controls were analyzed by liquid chromatography tandem mass spectrometry for sphingolipid content. Sphingosine-1-phosphate (S1P) and ceramide levels were validated in plasma samples from the Atopic Dermatitis Vaccinia Network/Atopic Dermatitis Research Network repository (12 NA, 12 AD, 23 EH) and plasma from 7 subjects with EV and 7 matched subjects with AD. S1P lyase was downregulated in human primary keratinocytes to evaluate its effect on herpes simplex virus 1 (HSV-1) replication in vitro. RESULTS: The stratum corneum of patients with EH demonstrated significantly higher levels of free sphingoid bases than those in patients who were NA, indicating enhanced sphingolipid turnover in keratinocytes (P < .05). Plasma from 2 independent cohorts of patients with EH had a significantly increased S1P/ceramide ratio in subjects with EH versus those with AD and or who were NA (P < .01). The S1P level in plasma from subjects with EV was twice the level in plasma from subjects with AD (mean = 1,533 vs 732 pmol/mL; P < .001). Downregulation of S1P lyase expression with silencing RNA led to an increased S1P level and doubled HSV-1 titer in keratinocytes. CONCLUSIONS: Our data point to long-term abnormalities in the S1P signaling system as a biomarker for previous disseminated viral diseases and a potential treatment target in recurring infections.

Polygenic prediction of atopic dermatitis improves with atopic training and filaggrin factors.

BACKGROUND: While numerous genetic loci associated with atopic dermatitis (AD) have been discovered, to date, work leveraging the combined burden of AD risk variants across the genome to predict disease risk has been limited. OBJECTIVES: This study aims to determine whether polygenic risk scores (PRSs) relying on genetic determinants for AD provide useful predictions for disease occurrence and severity. It also explicitly tests the value of including genome-wide association studies of related allergic phenotypes and known FLG loss-of-function (LOF) variants. METHODS: AD PRSs were constructed for 1619 European American individuals from the Atopic Dermatitis Research Network using an AD training dataset and an atopic training dataset including AD, childhood onset asthma, and general allergy. Additionally, whole genome sequencing data were used to explore genetic scoring specific to FLG LOF mutations. RESULTS: Genetic scores derived from the AD-only genome-wide association studies were predictive of AD cases (PRSAD: odds ratio [OR], 1.70; 95% CI, 1.49-1.93). Accuracy was first improved when PRSs were built off the larger atopy genome-wide association studies (PRSAD+: OR, 2.16; 95% CI, 1.89-2.47) and further improved when including FLG LOF mutations (PRSAD++: OR, 3.23; 95% CI, 2.57-4.07). Importantly, while all 3 PRSs correlated with AD severity, the best prediction was from PRSAD++, which distinguished individuals with severe AD from control subjects with OR of 3.86 (95% CI, 2.77-5.36). CONCLUSIONS: This study demonstrates how PRSs for AD that include genetic determinants across atopic phenotypes and FLG LOF variants may be a promising tool for identifying individuals at high risk for developing disease and specifically severe disease.

JAK Signaling Is Critically Important in Cytokine-Induced Viral Susceptibility of Keratinocytes.

Little is known about whether type 1 (IFNγ), 2 (IL-4/IL-13), or 3 (IL-17A/IL-22) cytokines affect the susceptibility of keratinocytes (KC) to viruses. These immune pathways predominate in various skin diseases: lupus, atopic dermatitis (AD), and psoriasis, respectively. Janus kinase inhibitors (JAKi) are approved to treat both AD and psoriasis, and are in clinical development for lupus. We evaluated whether these cytokines alter viral susceptibility of KC and determined if this effect is modulated by treatment with JAKi. Viral susceptibility to vaccinia virus (VV) or herpes simplex virus-1 (HSV-1) ± JAKi was assessed in immortalized and primary human KC pretreated with cytokines. Exposure to type 2 (IL-4 + IL-13) or the type 3 (IL-22) cytokines significantly increased KC viral susceptibility. Specifically, there was a peak increase of 12.2 ± 3.1-fold (IL-4 + IL-13) or 7.7 ± 2.8-fold (IL-22) in VV infection as measured by plaque number. Conversely, IFNγ significantly reduced susceptibility to VV (63.1 ± 64.4-fold). The IL-4 + IL-13-induced viral susceptibility was reduced (44 ± 16%) by JAK1 inhibition, while the IL-22-enhanced viral susceptibility was diminished (76 ± 19%) by TYK2 inhibition. IFNγ-mediated resistance to viral infection was reversed by JAK2 inhibition (366 ± 294% increase in infection). Cytokines expressed in AD skin (IL-4, IL-13, IL-22) increase KC viral susceptibility while IFNγ is protective. JAKi that target JAK1 or TYK2 reversed cytokine-enhanced viral susceptibility, while JAK2 inhibition reduced the protective effects of IFNγ.

Proposal of 0.5 mg of protein/100 g of processed food as threshold for voluntary declaration of food allergen traces in processed food-A first step in an initiative to better inform patients and avoid fatal allergic reactions: A GA²LEN position paper.

BACKGROUND: Food anaphylaxis is commonly elicited by unintentional ingestion of foods containing the allergen above the tolerance threshold level of the individual. While labeling the 14 main allergens used as ingredients in food products is mandatory in the EU, there is no legal definition of declaring potential contaminants. Precautionary allergen labeling such as "may contain traces of" is often used. However, this is unsatisfactory for consumers as they get no information if the contamination is below their personal threshold. In discussions with the food industry and technologists, it was suggested to use a voluntary declaration indicating that all declared contaminants are below a threshold of 0.5 mg protein per 100 g of food. This concentration is known to be below the threshold of most patients, and it can be technically guaranteed in most food production. However, it was also important to assess that in case of accidental ingestion of contaminants below this threshold by highly allergic patients, no fatal anaphylactic reaction could occur. Therefore, we performed a systematic review to assess whether a fatal reaction to 5mg of protein or less has been reported, assuming that a maximum portion size of 1kg of a processed food exceeds any meal and thus gives a sufficient safety margin. METHODS: MEDLINE and EMBASE were searched until 24 January 2021 for provocation studies and case reports in which one of the 14 major food allergens was reported to elicit fatal or life-threatening anaphylactic reactions and assessed if these occurred below the ingestion of 5mg of protein. A Delphi process was performed to obtain an expert consensus on the results. RESULTS: In the 210 studies included, in our search, no reports of fatal anaphylactic reactions reported below 5 mg protein ingested were identified. However, in provocation studies and case reports, severe reactions below 5 mg were reported for the following allergens: eggs, fish, lupin, milk, nuts, peanuts, soy, and sesame seeds. CONCLUSION: Based on the literature studied for this review, it can be stated that cross-contamination of the 14 major food allergens below 0.5 mg/100 g is likely not to endanger most food allergic patients when a standard portion of food is consumed. We propose to use the statement "this product contains the named allergens in the list of ingredients, it may contain traces of other contaminations (to be named, e.g. nut) at concentrations less than 0.5 mg per 100 g of this product" for a voluntary declaration on processed food packages. This level of avoidance of cross-contaminations can be achieved technically for most processed foods, and the statement would be a clear and helpful message to the consumers. However, it is clearly acknowledged that a voluntary declaration is only a first step to a legally binding solution. For this, further research on threshold levels is encouraged.

Infections in children and adolescents treated with dupilumab in pediatric clinical trials for atopic dermatitis-A pooled analysis of trial data.

BACKGROUND/OBJECTIVE: Patients with moderate-to-severe atopic dermatitis (AD) have increased risk of cutaneous and extracutaneous infections. Dupilumab has previously been associated with reduced risk of serious/severe infections and non-herpetic skin infections in adults with moderate-to-severe AD. This analysis assessed infection rates with dupilumab versus placebo in pediatric patients with moderate-to-severe and severe AD participating in clinical trials. METHODS: This is a pooled analysis from two 16-week, randomized, placebo-controlled, phase 3 clinical trials of dupilumab: monotherapy in adolescents aged 12-17 years with moderate-to-severe AD (LIBERTY AD ADOL, NCT03054428) and with concomitant topical corticosteroids in children aged 6-11 years with severe AD (LIBERTY AD PEDS, NCT03345914). Data were pooled according to treatment received: placebo/approved dupilumab doses/other studied dupilumab doses/all dupilumab doses. Exposure-adjusted rates (patients with ≥1 event per 100 patient-years [nP/100 PY]) were used to compare treatment groups. RESULTS: Overall, 612 patients were included: 205 received placebo and 407 received dupilumab (261 received approved dupilumab doses and 146 received other studied dupilumab doses). Overall infection rates were numerically lower with dupilumab versus placebo (nP/100 PY: placebo, 227; approved dupilumab, 173; other dupilumab, 206; all dupilumab, 184). Total skin infections were numerically less frequent in all dupilumab-treated groups versus placebo (nP/100 PY: placebo, 67; approved dupilumab, 30; other dupilumab, 46; all dupilumab, 36). CONCLUSIONS: These data suggest that dupilumab treatment in children and adolescents with AD does not increase infection risk overall and is associated with lower rates of skin infections compared with placebo.

Multiethnic genome-wide and HLA association study of total serum IgE level.

BACKGROUND: Total serum IgE (tIgE) is an important intermediate phenotype of allergic disease. Whole genome genetic association studies across ancestries may identify important determinants of IgE. OBJECTIVE: We aimed to increase understanding of genetic variants affecting tIgE production across the ancestry and allergic disease spectrum by leveraging data from the National Heart, Lung and Blood Institute Trans-Omics for Precision Medicine program; the Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA); and the Atopic Dermatitis Research Network (N = 21,901). METHODS: We performed genome-wide association within strata of study, disease, and ancestry groups, and we combined results via a meta-regression approach that models heterogeneity attributable to ancestry. We also tested for association between HLA alleles called from whole genome sequence data and tIgE, assessing replication of associations in HLA alleles called from genotype array data. RESULTS: We identified 6 loci at genome-wide significance (P < 5 × 10-9), including 4 loci previously reported as genome-wide significant for tIgE, as well as new regions in chr11q13.5 and chr15q22.2, which were also identified in prior genome-wide association studies of atopic dermatitis and asthma. In the HLA allele association study, HLA-A∗02:01 was associated with decreased tIgE level (Pdiscovery = 2 × 10-4; Preplication = 5 × 10-4; Pdiscovery+replication = 4 × 10-7), and HLA-DQB1∗03:02 was strongly associated with decreased tIgE level in Hispanic/Latino ancestry populations (PHispanic/Latino discovery+replication = 8 × 10-8). CONCLUSION: We performed the largest genome-wide association study and HLA association study of tIgE focused on ancestrally diverse populations and found several known tIgE and allergic disease loci that are relevant in non-European ancestry populations.

Skin barrier defects in atopic dermatitis: From old idea to new opportunity.

Atopic dermatitis (AD) is the most common chronic skin inflammatory disease, with a profound impact on patients' quality of life. AD varies considerably in clinical course, age of onset and degree to which it is accompanied by allergic and non-allergic comorbidities. Skin barrier impairment in both lesional and nonlesional skin is now recognized as a critical and often early feature of AD. This may be explained by a number of abnormalities identified within both the stratum corneum and stratum granulosum layers of the epidermis. The goal of this review is to provide an overview of key barrier defects in AD, starting with a historical perspective. We will also highlight some of the commonly used methods to characterize and quantify skin barrier function. There is ample opportunity for further investigative work which we call out throughout this review. These include: quantifying the relative impact of individual epidermal abnormalities and putting this in a more holistic view with physiological measures of barrier function, as well as determining whether these barrier-specific endotypes predict clinical phenotypes (e.g. age of onset, natural history, comorbidities, response to therapies, etc). Mechanistic studies with new (and in development) AD therapies that specifically target immune pathways, Staphylococcus aureus abundance and/or skin barrier will help us understand the dynamic crosstalk between these compartments and their relative importance in AD.

Whole genome sequencing identifies novel genetic mutations in patients with eczema herpeticum.

BACKGROUND: Eczema herpeticum (EH) is a rare complication of atopic dermatitis (AD) caused by disseminated herpes simplex virus (HSV) infection. The role of rare and/or deleterious genetic variants in disease etiology is largely unknown. This study aimed to identify genes that harbor damaging genetic variants associated with HSV infection in AD with a history of recurrent eczema herpeticum (ADEH+). METHODS: Whole genome sequencing (WGS) was performed on 49 recurrent ADEH+ (≥3 EH episodes), 491 AD without a history of eczema herpeticum (ADEH-) and 237 non-atopic control (NA) subjects. Variants were annotated, and a gene-based approach (SKAT-O) was used to identify genes harboring damaging genetic variants associated with ADEH+. Genes identified through WGS were studied for effects on HSV responses and keratinocyte differentiation. RESULTS: Eight genes were identified in the comparison of recurrent ADEH+to ADEH-and NA subjects: SIDT2, CLEC7A, GSTZ1, TPSG1, SP110, RBBP8NL, TRIM15, and FRMD3. Silencing SIDT2 and RBBP8NL in normal human primary keratinocytes (NHPKs) led to significantly increased HSV-1 replication. SIDT2-silenced NHPKs had decreased gene expression of IFNk and IL1b in response to HSV-1 infection. RBBP8NL-silenced NHPKs had decreased gene expression of IFNk, but increased IL1b. Additionally, silencing SIDT2 and RBBP8NL also inhibited gene expression of keratinocyte differentiation markers keratin 10 (KRT10) and loricrin (LOR). CONCLUSION: SIDT2 and RBBP8NL participate in keratinocyte's response to HSV-1 infection. SIDT2 and RBBP8NL also regulate expression of keratinocyte differentiation genes of KRT10 and LOR.

On the cause and consequences of IgE to galactose-α-1,3-galactose: A report from the National Institute of Allergy and Infectious Diseases Workshop on Understanding IgE-Mediated Mammalian Meat Allergy.

The mammalian meat allergy known as the "α-Gal syndrome" relates to IgE specific for galactose-α-1,3-galactose (α-Gal), an oligosaccharide that is present in cells and tissues of nonprimate mammals. The recognition of delayed reactions to food derived from mammals in patients with IgE to α-Gal and also the association with tick bites have been increasing worldwide. In 2018, the National Institute of Allergy and Infectious Diseases, Division of Allergy, Immunology and Transplantation, sponsored a workshop on this emerging tick-related disease. International experts from the fields of tick biology, allergy, immunology, infectious disease, and dermatology discussed the current state of our understanding of this emerging medical condition. The participants provided suggestions for specific research priorities and for the development of resources to advance our knowledge of the mechanisms, diagnosis, management, and prevention of this allergic disease. This publication is a summary of the workshop and the panel's recommendations are presented herein.