Phenotypic and Endotypic Determinants of Atopic Dermatitis Severity From the Atopic Dermatitis Research Network (ADRN) Registry

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin condition with a highly variable clinical phenotype.

OBJECTIVE

This study aimed to identify historical and clinical features and biomarkers associated with AD severity.

METHODS

A US registry of extensively phenotyped AD participants (aged 0.73-80 years) were enrolled at 9 academic centers. Information on family and personal medical history, examination, skin swabs (culture), and serum biomarkers was collected to evaluate their association with AD severity.

RESULTS

Participants with AD (N = 2862) whose disease was categorized as mild (11.6%), moderate (58.0%), or severe (30.4%) based on Rajka-Langeland scoring were enrolled. The trend test, when adjusting for gender, race, and age, demonstrated that severity was strongly (P ≤ .04) associated with a personal/family history of allergic disorders, history of alopecia, exposure to passive smoke, ocular herpes infection, skin bacterial and viral infections, and history of arrhythmia. Features observed more frequently (P ≤ .002), as a function of severity, included skin infections (impetigo, human papillomavirus, and molluscum contagiosum virus), Staphylococcus aureus colonization, excoriations, hyperlinear palms, ichthyosis, blepharitis, conjunctivitis, ectropion, and wheezing. Serum IgE, allergen and food (≤6 years) Phadiatop, and eosinophilia were strongly linked to severity (P < .001).

CONCLUSIONS

In a diverse US AD population, severity was associated with a history of atopic disorders, skin and extracutaneous bacterial and viral infections (by history and physical examination), higher IgE, eosinophilia and allergen sensitization, atopic skin manifestations (ie, excoriation, hyperlinear palms, and ichthyosis), and atopic ocular features (ie, blepharitis, conjunctivitis, and ectropion) as well as asthma findings (ie, wheezing). Data from our prospective registry significantly advance our understanding of AD phenotypes and endotypes, which is critical to achieve optimal management.

Air Pollution and Atopic Dermatitis, from Molecular Mechanisms to Population-Level Evidence: A Review

Atopic dermatitis (AD) has increased in prevalence to become the most common inflammatory skin condition globally, and geographic variation and migration studies suggest an important role for environmental triggers. Air pollution, especially due to industrialization and wildfires, may contribute to the development and exacerbation of AD. We provide a comprehensive, multidisciplinary review of existing molecular and epidemiologic studies on the associations of air pollutants and AD symptoms, prevalence, incidence, severity, and clinic visits. Cell and animal studies demonstrated that air pollutants contribute to AD symptoms and disease by activating the aryl hydrocarbon receptor pathway, promoting oxidative stress, initiating a proinflammatory response, and disrupting the skin barrier function. Epidemiologic studies overall report that air pollution is associated with AD among both children and adults, though the results are not consistent among cross-sectional studies. Studies on healthcare use for AD found positive correlations between medical visits for AD and air pollutants. As the air quality worsens in many areas globally, it is important to recognize how this can increase the risk for AD, to be aware of the increased demand for AD-related medical care, and to understand how to counsel patients regarding their skin health. Further research is needed to develop treatments that prevent or mitigate air pollution-related AD symptoms.

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.

New and developing therapies for atopic dermatitis

Atopic dermatitis is a common inflammatory skin disease. New understanding in disease pathogenesis has led to a considerable number of promising new drugs in development. New topical agents can be especially helpful for children, providing an alternative to the need for chronic topical corticosteroid use. While many patients with mild or moderate disease can be managed with topical treatments, there are unmet needs for recalcitrant and severe cases. New and developing therapies hold promise for real advances in management of this complex disease.

Validation of a Parent-Reported Diagnostic Instrument in a U.S. Referral Population: The Childhood Eczema Questionnaire

BACKGROUND/OBJECTIVES

There is a paucity of validated tools for diagnosing atopic dermatitis (AD) in very young children that do not rely on clinical evaluation. The Childhood Eczema Questionnaire (CEQ)-a diagnostic tool for AD in children younger than 2 years that a caretaker can complete-was recently validated in Sweden. The objective of this study was to validate the tool in a U.S.

POPULATION

As a substudy, we added an additional question that was independently assessed.

METHODS

Children younger than 2 years old were recruited from a dermatology clinic. Their caretakers completed a questionnaire containing the original tool's three questions as well as a fourth question that increased the time frame measured from 1 week to 6 months. Questionnaires with all "yes" answers were considered positive and were compared with a dermatologist diagnosis of AD.

RESULTS

A total of 283 subjects were recruited. The first three questions (the original CEQ) predicted a positive diagnosis of AD with a sensitivity of 0.72 (95% confidence interval [CI] 0.58, 0.82) and a specificity of 0.93 (95% CI 0.87, 0.95). In a separate analysis we included the first two questions and the fourth question and found that the sensitivity increased to 0.82 (95% CI 0.69, 0.90) with a specificity of 0.89 (95% CI 0.83, 0.93).

CONCLUSION

This study validates a novel parental questionnaire for the diagnosis of AD in children younger than 2 years in a U.S. clinic population.

Anti-Interleukin-31 Receptor A Antibody for Atopic Dermatitis

BACKGROUND

Interleukin-31 may play a role in the pathobiologic mechanism of atopic dermatitis and pruritus. We wanted to assess the efficacy and safety of nemolizumab (CIM331), a humanized antibody against interleukin-31 receptor A, in the treatment of atopic dermatitis.

METHODS

In this phase 2, randomized, double-blind, placebo-controlled, 12-week trial, we assigned adults with moderate-to-severe atopic dermatitis that was inadequately controlled by topical treatments to receive subcutaneous nemolizumab (at a dose of 0.1 mg, 0.5 mg, or 2.0 mg per kilogram of body weight) or placebo every 4 weeks or an exploratory dose of 2.0 mg of nemolizumab per kilogram every 8 weeks. The primary end point was the percentage improvement from baseline in the score on the pruritus visual-analogue scale (on which a negative change indicates improvement) at week 12. Secondary end points included changes in the score on the Eczema Area and Severity Index (EASI, on which a negative change indicates improvement), and body-surface area of atopic dermatitis.

RESULTS

Of 264 patients who underwent randomization, 216 (82%) completed the study. At week 12, among the patients who received nemolizumab every 4 weeks, changes on the pruritus visual-analogue scale were -43.7% in the 0.1-mg group, -59.8% in the 0.5-mg group, and -63.1% in the 2.0-mg group, versus -20.9% in the placebo group (P<0.01 for all comparisons). Changes on the EASI were -23.0%, -42.3%, and -40.9%, respectively, in the nemolizumab groups, versus -26.6% in the placebo group. Respective changes in body-surface area affected by atopic dermatitis were -7.5%, -20.0%, and -19.4% with nemolizumab, versus -15.7% with placebo. Among the patients receiving nemolizumab every 4 weeks, treatment discontinuations occurred in 9 of 53 patients (17%) in the 0.1-mg group, in 9 of 54 (17%) in the 0.5-mg group, and in 7 of 52 (13%) in the 2.0-mg group, versus in 9 of 53 (17%) in the placebo group.

CONCLUSIONS

In this phase 2 trial, nemolizumab at all monthly doses significantly improved pruritus in patients with moderate-to-severe atopic dermatitis, which showed the efficacy of targeting interleukin-31 receptor A. The limited size and length of the trial preclude conclusions regarding adverse events. (Funded by Chugai Pharmaceutical; XCIMA ClinicalTrials.gov number, NCT01986933 .).

A clinical trial of intradermal and intramuscular seasonal influenza vaccination in patients with atopic dermatitis

BACKGROUND

Antibody responses to the inactivated seasonal influenza vaccine in patients with atopic dermatitis (AD) have not been carefully characterized.

OBJECTIVE

The primary objective of this study was to compare antibody responses to intradermal vaccination in participants with moderate/severe AD with those in nonatopic participants. Secondary objectives were to evaluate the effect of route of administration, Staphylococcus aureus skin colonization, and disease severity on vaccine response.

METHODS

This was an open-label study conducted in the 2012-2013 influenza season at 5 US clinical sites. A total of 360 participants with moderate/severe AD or nonatopic subjects were assessed for eligibility, 347 of whom received intradermal or intramuscular vaccination per label and were followed for 28 days after vaccination. The primary outcome was the difference in the proportion of participants achieving seroprotection (hemagglutination-inhibition antibody titer ≥1:40 on day 28 after vaccination).

RESULTS

Seroprotection rates for influenza B, H1N1, and H3N2 were not different (1) between participants with AD and nonatopic participants receiving intradermal vaccination and (2) between AD participants receiving intradermal and intramuscular vaccination. After intradermal, but not intramuscular, vaccination, participants with AD with S aureus colonization experienced (1) lower seroprotection and seroconversion rates and lower hemagglutination-inhibition antibody titer geometric mean fold increase against influenza B and (2) lower seroconversion rates against influenza H1N1 than noncolonized participants with AD.

CONCLUSION

Participants with AD colonized with S aureus exhibited a reduced immune response to influenza vaccination compared with noncolonized participants after intradermal but not intramuscular vaccination. Because most patients with AD are colonized with S aureus, intramuscular influenza vaccination should be given preference in these patients.

Targeted deep sequencing identifies rare loss-of-function variants in IFNGR1 for risk of atopic dermatitis complicated by eczema herpeticum

BACKGROUND

A subset of atopic dermatitis is associated with increased susceptibility to eczema herpeticum (ADEH+). We previously reported that common single nucleotide polymorphisms (SNPs) in the IFN-γ (IFNG) and IFN-γ receptor 1 (IFNGR1) genes were associated with the ADEH+ phenotype.

OBJECTIVE

We sought to interrogate the role of rare variants in interferon pathway genes for the risk of ADEH+.

METHODS

We performed targeted sequencing of interferon pathway genes (IFNG, IFNGR1, IFNAR1, and IL12RB1) in 228 European American patients with AD selected according to their eczema herpeticum status, and severity was measured by using the Eczema Area and Severity Index. Replication genotyping was performed in independent samples of 219 European American and 333 African American subjects. Functional investigation of loss-of-function variants was conducted by using site-directed mutagenesis.

RESULTS

We identified 494 single nucleotide variants encompassing 105 kb of sequence, including 145 common, 349 (70.6%) rare (minor allele frequency <5%), and 86 (17.4%) novel variants, of which 2.8% were coding synonymous, 93.3% were noncoding (64.6% intronic), and 3.8% were missense. We identified 6 rare IFNGR1 missense variants, including 3 damaging variants (Val14Met [V14M], Val61Ile, and Tyr397Cys [Y397C]) conferring a higher risk for ADEH+ (P = .031). Variants V14M and Y397C were confirmed to be deleterious, leading to partial IFNGR1 deficiency. Seven common IFNGR1 SNPs, along with common protective haplotypes (2-7 SNPs), conferred a reduced risk of ADEH+ (P = .015-.002 and P = .0015-.0004, respectively), and both SNP and haplotype associations were replicated in an independent African American sample (P = .004-.0001 and P = .001-.0001, respectively).

CONCLUSION

Our results provide evidence that both genetic variants in the gene encoding IFNGR1 are implicated in susceptibility to the ADEH+ phenotype.

Food Allergy in Infants With Atopic Dermatitis: Limitations of Food-Specific IgE Measurements

BACKGROUND AND OBJECTIVES

Children with atopic dermatitis (AD) have a higher risk for development of food allergies. The objective of this study was to examine incidence of food allergy development in infants with AD and the predictive value of food-antigen-specific immunoglobulin E measurements.

METHODS

This trial examined the long-term safety and efficacy of pimecrolimus cream 1% in >1000 infants (3-18 months) with mild-to-severe AD without a history of food allergy. Food allergy development was followed throughout a 36-month randomized double-blind phase followed by an open-label (OL) phase up to 33 months. Additionally, sIgE for cow's milk, egg white, peanut, wheat, seafood mix, and soybean was measured by ImmunoCAP at baseline, end of the double-blind phase, and end of OL phase.

RESULTS

By the end of the OL phase, 15.9% of infants with AD developed at least 1 food allergy; allergy to peanut was most common (6.6%), followed by cow's milk (4.3%) and egg white (3.9%). Seafood, soybean, and wheat allergies were rare. Levels of sIgE for milk, egg, and peanut increased with severity of AD, as determined by Investigator's Global Assessment score. We assigned sIgE decision points for the 6 foods and tested their ability to predict definite food allergy in this population. Positive predictive values for published and newly developed sIgE decision points were low (<0.6 for all values tested).

CONCLUSIONS

In a large cohort of infants at risk for development of food allergy, sIgE levels were not clinically useful for predicting food allergy development.

Emollient enhancement of the skin barrier from birth offers effective atopic dermatitis prevention

Background

Atopic dermatitis (atopic eczema) is a chronic inflammatory skin disease that has reached epidemic proportions in children worldwide and is increasing in prevalence. Because of the significant socioeconomic effect of atopic dermatitis and its effect on the quality of life of children and families, there have been decades of research focused on disease prevention, with limited success. Recent advances in cutaneous biology suggest skin barrier defects might be key initiators of atopic dermatitis and possibly allergic sensitization.

Objective

Our objective was to test whether skin barrier enhancement from birth represents a feasible strategy for reducing the incidence of atopic dermatitis in high-risk neonates.

Methods

We performed a randomized controlled trial in the United States and United Kingdom of 124 neonates at high risk for atopic dermatitis. Parents in the intervention arm were instructed to apply full-body emollient therapy at least once per day starting within 3 weeks of birth. Parents in the control arm were asked to use no emollients. The primary feasibility outcome was the percentage of families willing to be randomized. The primary clinical outcome was the cumulative incidence of atopic dermatitis at 6 months, as assessed by a trained investigator.

Results

Forty-two percent of eligible families agreed to be randomized into the trial. All participating families in the intervention arm found the intervention acceptable. A statistically significant protective effect was found with the use of daily emollient on the cumulative incidence of atopic dermatitis with a relative risk reduction of 50% (relative risk, 0.50; 95% CI, 0.28-0.9; P = .017). There were no emollient-related adverse events and no differences in adverse events between groups.

Conclusion

The results of this trial demonstrate that emollient therapy from birth represents a feasible, safe, and effective approach for atopic dermatitis prevention. If confirmed in larger trials, emollient therapy from birth would be a simple and low-cost intervention that could reduce the global burden of allergic diseases.

A systematic review of topical corticosteroid withdrawal ("steroid addiction") in patients with atopic dermatitis and other dermatoses

BACKGROUND

The National Eczema Association has received increasing numbers of patient inquiries regarding "steroid addiction syndrome," coinciding with the growing presence of social media dedicated to this topic. Although many of the side effects of topical corticosteroids (TCS) are addressed in guidelines, TCS addiction is not.

OBJECTIVE

We sought to assess the current evidence regarding addiction/withdrawal.

METHODS

We performed a systematic review of the current literature.

RESULTS

Our initial search yielded 294 results with 34 studies meeting inclusion criteria. TCS withdrawal was reported mostly on the face and genital area (99.3%) of women (81.0%) primarily in the setting of long-term inappropriate use of potent TCS. Burning and stinging were the most frequently reported symptoms (65.5%) with erythema being the most common sign (92.3%). TCS withdrawal syndrome can be divided into papulopustular and erythematoedematous subtypes, with the latter presenting with more burning and edema.

LIMITATIONS

Low quality of evidence, variability in the extent of data, and the lack of studies with rigorous steroid addiction methodology are limitations.

CONCLUSIONS

TCS withdrawal is likely a distinct clinical adverse effect of TCS misuse. Patients and providers should be aware of its clinical presentation and risk factors.

Report from the third international consensus meeting to harmonise core outcome measures for atopic eczema/dermatitis clinical trials (HOME)

This report provides a summary of the third meeting of the Harmonising Outcome Measures for Eczema (HOME) initiative held in San Diego, CA, U.S.A., 6-7 April 2013 (HOME III). The meeting addressed the four domains that had previously been agreed should be measured in every eczema clinical trial: clinical signs, patient-reported symptoms, long-term control and quality of life. Formal presentations and nominal group techniques were used at this working meeting, attended by 56 voting participants (31 of whom were dermatologists). Significant progress was made on the domain of clinical signs. Without reference to any named scales, it was agreed that the intensity and extent of erythema, excoriation, oedema/papulation and lichenification should be included in the core outcome measure for the scale to have content validity. The group then discussed a systematic review of all scales measuring the clinical signs of eczema and their measurement properties, followed by a consensus vote on which scale to recommend for inclusion in the core outcome set. Research into the remaining three domains was presented, followed by discussions. The symptoms group and quality of life groups need to systematically identify all available tools and rate the quality of the tools. A definition of long-term control is needed before progress can be made towards recommending a core outcome measure.

Atopic dermatitis complicated by eczema herpeticum is associated with HLA B7 and reduced interferon-γ-producing CD8+ T cells

BACKGROUND

The increased susceptibility of patients with atopic dermatitis (AD) to disseminated viral skin infections such as eczema herpeticum (ADEH+) is poorly understood.

OBJECTIVES

The primary goal of the current study was to determine whether ADEH+ subjects have identifiable defects in cell-mediated immunity that reduce their ability to control viral infections.

MATERIALS AND METHODS

In this study, we evaluated cytokine expression by various subsets of peripheral blood mononuclear cells from ADEH+ (n = 24) compared with AD without a history of viral infections (ADEH-) (n = 20) before and after treatment with herpes simplex virus (HSV).

RESULTS

We found that interferon (IFN)-γ expression after HSV treatment was lower in the CD8+ T cells and monocytes from patients with ADEH+ compared with patients who are ADEH- or nonatopic. Given the induction of CD8+ T cells as the result of antigen presentation by human leucocyte antigen (HLA) class I, consistent with the findings described above we also found that the HLA B7 allele was significantly associated with risk of the ADEH+ phenotype (odds ratio = 1·91, P = 0·02, 125 ADEH+ and 161 ADEH- subjects).

CONCLUSIONS

These data suggest that defects in viral-induced IFN-γ from CD8+ T cells contribute to the ADEH+ phenotype.

Guidelines of care for the management of atopic dermatitis: section 3. Management and treatment with phototherapy and systemic agents

Atopic dermatitis is a chronic, pruritic inflammatory dermatosis that affects up to 25% of children and 2% to 3% of adults. This guideline addresses important clinical questions that arise in atopic dermatitis management and care, providing recommendations based on the available evidence. In this third of 4 sections, treatment of atopic dermatitis with phototherapy and systemic immunomodulators, antimicrobials, and antihistamines is reviewed, including indications for use and the risk-benefit profile of each treatment option.

Reversion of methicillin-resistant Staphylococcus aureus skin infections to methicillin-susceptible isolates

IMPORTANCE

The rise of methicillin-resistant Staphylococcus aureus (MRSA) infections in the outpatient setting has led to a growing trend of empirical antibiotic treatment for MRSA. The limited oral antibiotics available and the growing resistance to these antibiotics make this a controversial practice.

OBJECTIVE

To determine the frequency of patients with MRSA skin and soft-tissue infections (SSTIs) reverting to methicillin-susceptible Staphylococcus aureus (MSSA) positivity.

DESIGN AND SETTING

Retrospective medical record review of inpatients and outpatients from our university hospital and clinics between January 1, 2000, and December 31, 2010.

PARTICIPANTS

Patients in our institutional microbiological database were included if they had a MRSA-positive SSTI and subsequent culture-proven S aureus SSTI more than 1 month later. No sociodemographic restrictions were applied. A sample of at least 200 patients meeting the above criteria was desired. The database was sorted by ascending medical record number, with the first 1681 patients' medical records reviewed. Of these, 215 patients met our criteria.

MAIN OUTCOMES AND MEASURES

Whether a patient remained MRSA positive in subsequent SSTIs or reverted to MSSA-positive infections.

RESULTS

Of the total 215 patients, 64 (29.8%) had at least 1 incident of MSSA reversion, and 55 (25.6%) reverted to MSSA infections for the remainder of the study. We assessed various factors that might increase or decrease the likelihood of reversion. The presence of an invasive device was the only factor to demonstrate a statistically significant risk (relative risk, 1.20; 95% CI, 1.02-1.41; P = .03) toward remaining MRSA positive in subsequent infections.

CONCLUSIONS AND RELEVANCE

Patients with MRSA SSTIs demonstrated the ability to revert to subsequent MSSA SSTIs with a significant frequency. Further study regarding MRSA risk factors and their effects on subsequent infections would be valuable in guiding empirical treatment. Reculturing new infections in previously MRSA-positive patients is a prudent management strategy as we recognize that susceptibilities of the S aureus organisms change.

Guidelines of care for the management of atopic dermatitis: section 1. Diagnosis and assessment of atopic dermatitis

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory dermatosis that affects up to 25% of children and 2% to 3% of adults. This guideline addresses important clinical questions that arise in the management and care of AD, providing updated and expanded recommendations based on the available evidence. In this first of 4 sections, methods for the diagnosis and monitoring of disease, outcomes measures for assessment, and common clinical associations that affect patients with AD are discussed. Known risk factors for the development of disease are also reviewed.

Adult eczema prevalence and associations with asthma and other health and demographic factors: a US population-based study

BACKGROUND

Little is known about the epidemiology of eczema in adults. The goal of this study was to determine the prevalence of and associations with adult eczema in the United States.

METHODS

We used the 2010 National Health Interview Survey from a nationally representative sample of 27,157 adults age 18 to 85 years.

RESULTS

Overall, the 1-year prevalence of eczema was 10.2% (95% CI, 9.7% to 10.6%). The 1-year prevalence of eczema with asthma and/or hay fever was 3.2% (95% CI, 2.8% to 3.3%). Adult eczema was associated with higher prevalence of asthma (P < .001, Rao-Scott χ(2) test), more asthma attacks in the past year (P < .001), and more persistent asthma (P = .02). In multivariate models eczema prevalence was significantly higher in older participants; female subjects; those with Hispanic ethnicity, US birthplace, and higher level of household education; and those currently working (all P ≤ .02, logistic regression).

CONCLUSIONS

This study provides US population-based estimates of eczema prevalence and asthma associations in adults. The results suggest multiple demographic and socioeconomic influences on the US prevalence of adult eczema.

A randomized controlled double-blind investigation of the effects of vitamin D dietary supplementation in subjects with atopic dermatitis

BACKGROUND

Subjects with atopic dermatitis (AD) have defects in antimicrobial peptide (AMP) production possibly contributing to an increased risk of infections. In laboratory models, vitamin D can alter innate immunity by increasing AMP production.

OBJECTIVE

To determine if AD severity correlates with baseline vitamin D levels, and to test whether supplementation with oral vitamin D alters AMP production in AD skin.

METHODS

This was a multi-centre, placebo-controlled, double-blind study in 30 subjects with AD, 30 non-atopic subjects, and 16 subjects with psoriasis. Subjects were randomized to receive either 4000 IU of cholecalciferol or placebo for 21 days. At baseline and day 21, levels of 25-hydroxyvitamin D (25OHD), cathelicidin, HBD-3, IL-13, and Eczema Area and Severity Index (EASI) and Rajka-Langeland scores were obtained.

RESULTS

At baseline, 20% of AD subjects had serum 25OHD below 20 ng/mL. Low serum 25OHD correlated with increased Fitzpatrick Skin Type and elevated BMI, but not AD severity. After 21 days of oral cholecalciferol, mean serum 25OHD increased, but there was no significant change in skin cathelicidin, HBD-3, IL-13 or EASI scores.

CONCLUSIONS

This study illustrated that darker skin types and elevated BMI are important risk factors for vitamin D deficiency in subjects with AD, and highlighted the possibility that seasonality and locale may be potent contributors to cathelicidin induction through their effect on steady state 25OHD levels. Given the molecular links between vitamin D and immune function, further study of vitamin D supplementation in subjects with AD is warranted.

Is food allergy testing reliable in pediatric atopic dermatitis? A population-based study

We sought to assess the value and reliability of serologic testing for predicting clinical food allergy in a population-based cohort of infants with atopic dermatitis (AD). Infants 3-18 months of age, recruited from the general population, were followed quarterly for 3 years and carefully evaluated for evidence of immediate reactions to foods. Specific serum IgE levels for six foods were assayed at 3-5 years. Parents were interviewed at each visit regarding past/current immediate food-specific reactions involving skin, gut or respiratory systems. Data were entered into Excel for calculations of performance characteristics. Nine of the 40 patients (23%) who completed 3 years of follow-up had reactions to one or more foods. Reactions occurred in 5, 11 and 18% to milk, peanut and egg ingestion, respectively. In contrast, 30% of food-specific serum IgE tests were above normal. Predictive reliability of tests was generally low unless values were in the high range for peanut and milk. Conversely, egg allergy could be seen across a nearly full-spectrum of IgE values, making prediction highly unreliable. We conclude that physician and patient misinterpretation of the relevance and reliability of allergy testing may misdirect proper prevention and therapy of AD.

Genetic variants in interferon regulatory factor 2 (IRF2) are associated with atopic dermatitis and eczema herpeticum

Interferon regulatory factor 2 (IRF2) is a member of a family of transcriptional factors involved in the modulation of interferon induced immune responses to viral infection. To test whether genetic variants in IRF2 predict risk of AD and ADEH, we genotyped 78 IRF2 tagging single nucleotide polymorphisms (SNPs) in both European American (n=435) and African American (n = 339) populations. Significant associations were observed between AD and two SNPs (rs793814, P = 0.007, odds ratio (OR) = 0.52; rs3756094, P = 0.037, OR = 0.66) among European Americans and one SNP (rs3775572, P = 0.016, OR = 0.46) among African Americans. Significant associations were also observed between ADEH and five SNPs (P = 0.049-0.022) among European Americans. The association with ADEH was further strengthened by haplotype analyses, wherein a 5-SNP (CAGGA) haplotype showed the strongest association with ADEH (P = 0.0008). Eight IRF2 SNPs were significantly associated with IFNγ production post-herpes simplex virus (HSV) stimulation (P = 0.048-0.0008), including an AD-associated SNP (rs13139310, P = 0.008). Our findings suggest distinct markers in IRF2 may be associated with AD and ADEH, which may depend upon ethnic ancestry, and genetic variants in IRF2 may contribute to an abnormal immune response to HSV.

The signal transducer and activator of transcription 6 gene (STAT6) increases the propensity of patients with atopic dermatitis toward disseminated viral skin infections

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with increased susceptibility to recurrent skin infections.

OBJECTIVE

We sought to determine why a subset of patients with AD have an increased risk of disseminated viral skin infections.

METHODS

Human subjects with AD with a history of eczema herpeticum (EH) and various control groups were enrolled. Vaccinia virus (VV) expression was measured by means of PCR and immunofluorescent staining in skin biopsy specimens from each study group after incubation with VV. Transgenic mice with a constitutively active signal transducer and activator of transcription 6 gene (STAT6) were characterized for response to VV skin inoculation. Genotyping for 10 STAT6 single nucleotide polymorphisms (SNPs) was performed in a white patient sample (n = 444).

RESULTS

VV gene and protein expression were significantly increased in the skin of patients with EH compared with other subject groups after incubation with VV in vitro. Antibody neutralization of IL-4 and IL-13 resulted in lower VV replication in patients with a history of EH. Mice that expressed a constitutively active STAT6 gene compared with wild-type mice had increased mortality and satellite lesion formation after VV skin inoculation. Significant associations were observed between STAT6 SNPs and EH (rs3024975, rs841718, rs167769, and rs703817) and IFN-γ production. The strongest association was observed for a 2-SNP haplotype (patients with AD with a history of EH vs patients with AD without a history of EH, 24.9% vs 9.2%; P = 5.17 × 10(-6)).

CONCLUSION

The STAT6 gene increases viral replication in the skin of patients with AD with a history of EH. Further genetic association studies and functional investigations are warranted.

Human atopic dermatitis complicated by eczema herpeticum is associated with abnormalities in IFN-γ response

BACKGROUND

The basis for increased susceptibility of patients with atopic dermatitis (AD) to develop disseminated viral skin infections such as eczema herpeticum (AD with a history of eczema herpeticum, ADEH(+)) is poorly understood.

OBJECTIVE

We sought to determine whether subjects with AD prone to disseminated viral skin infections have defects in their IFN responses.

METHODS

GeneChip profiling was used to identify differences in gene expression of PBMCs from patients with ADEH(+) compared with patients with AD without a history of eczema herpeticum (ADEH(-)) and nonatopic controls. Key differences in protein expression were verified by enzyme-linked immunosorbent spot assay and/or ELISA. Clinical relevance was further demonstrated by a mouse model of disseminated viral skin infection and genetic association analysis for genetic variants in IFNG and IFNGR1 and ADEH among 435 cases and controls.

RESULTS

We demonstrate by global gene expression analysis selective transcriptomic changes within the IFN superfamily of PBMCs from subjects with ADEH(+) reflecting low IFN-γ and IFN-γ receptor gene expression. IFN-γ protein production was also significantly lower in patients with ADEH(+) (n = 24) compared with patients with ADEH(-) (n = 20) and nonatopic controls (n = 20). IFN-γ receptor knockout mice developed disseminated viral skin infection after epicutaneous challenge with vaccinia virus. Genetic variants in IFNG and IFNGR1 single nucleotide polymorphisms (SNPs) were significantly associated with ADEH (112 cases, 166 controls) and IFN-γ production: a 2-SNP (A-G) IFNGR1 haplotype (rs10457655 and rs7749390) showed the strongest association with a reduced risk of ADEH+ (13.2% ADEH(+) vs 25.5% ADEH(-); P = .00057).

CONCLUSION

Patients with ADEH(+) have reduced IFN-γ production, and IFNG and IFNGR1 SNPs are significantly associated with ADEH(+) and may contribute to an impaired immune response to herpes simplex virus.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

Tight junction defects in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is characterized by dry skin and a hyperactive immune response to allergens, 2 cardinal features that are caused in part by epidermal barrier defects. Tight junctions (TJs) reside immediately below the stratum corneum and regulate the selective permeability of the paracellular pathway.

OBJECTIVE

We evaluated the expression/function of the TJ protein claudin-1 in epithelium from AD and nonatopic subjects and screened 2 American populations for single nucleotide polymorphisms in the claudin-1 gene (CLDN1).

METHODS

Expression profiles of nonlesional epithelium from patients with extrinsic AD, nonatopic subjects, and patients with psoriasis were generated using Illumina's BeadChips. Dysregulated intercellular proteins were validated by means of tissue staining and quantitative PCR. Bioelectric properties of epithelium were measured in Ussing chambers. Functional relevance of claudin-1 was assessed by using a knockdown approach in primary human keratinocytes. Twenty-seven haplotype-tagging SNPs in CLDN1 were screened in 2 independent populations with AD.

RESULTS

We observed strikingly reduced expression of the TJ proteins claudin-1 and claudin-23 only in patients with AD, which were validated at the mRNA and protein levels. Claudin-1 expression inversely correlated with T(H)2 biomarkers. We observed a remarkable impairment of the bioelectric barrier function in AD epidermis. In vitro we confirmed that silencing claudin-1 expression in human keratinocytes diminishes TJ function while enhancing keratinocyte proliferation. Finally, CLDN1 haplotype-tagging SNPs revealed associations with AD in 2 North American populations.

CONCLUSION

Collectively, these data suggest that an impairment in tight junctions contributes to the barrier dysfunction and immune dysregulation observed in AD subjects and that this may be mediated in part by reductions in claudin-1.

Tight junction defects in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is characterized by dry skin and a hyperactive immune response to allergens, 2 cardinal features that are caused in part by epidermal barrier defects. Tight junctions (TJs) reside immediately below the stratum corneum and regulate the selective permeability of the paracellular pathway.

OBJECTIVE

We evaluated the expression/function of the TJ protein claudin-1 in epithelium from AD and nonatopic subjects and screened 2 American populations for single nucleotide polymorphisms in the claudin-1 gene (CLDN1).

METHODS

Expression profiles of nonlesional epithelium from patients with extrinsic AD, nonatopic subjects, and patients with psoriasis were generated using Illumina's BeadChips. Dysregulated intercellular proteins were validated by means of tissue staining and quantitative PCR. Bioelectric properties of epithelium were measured in Ussing chambers. Functional relevance of claudin-1 was assessed by using a knockdown approach in primary human keratinocytes. Twenty-seven haplotype-tagging SNPs in CLDN1 were screened in 2 independent populations with AD.

RESULTS

We observed strikingly reduced expression of the TJ proteins claudin-1 and claudin-23 only in patients with AD, which were validated at the mRNA and protein levels. Claudin-1 expression inversely correlated with T(H)2 biomarkers. We observed a remarkable impairment of the bioelectric barrier function in AD epidermis. In vitro we confirmed that silencing claudin-1 expression in human keratinocytes diminishes TJ function while enhancing keratinocyte proliferation. Finally, CLDN1 haplotype-tagging SNPs revealed associations with AD in 2 North American populations.

CONCLUSION

Collectively, these data suggest that an impairment in tight junctions contributes to the barrier dysfunction and immune dysregulation observed in AD subjects and that this may be mediated in part by reductions in claudin-1.

Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel

Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.

A pilot study of emollient therapy for the primary prevention of atopic dermatitis

BACKGROUND

Prevention strategies in atopic dermatitis (AD) using allergen avoidance have not been consistently effective. New research reveals the importance of the skin barrier in the development of AD and possibly food allergy and asthma. Correcting skin barrier defects from birth may prevent AD onset or moderate disease severity.

OBJECTIVE

We sought to determine the feasibility of skin barrier protection as a novel AD prevention strategy.

METHODS

We enrolled 22 neonates at high risk for developing AD in a feasibility pilot study using emollient therapy from birth.

RESULTS

No intervention-related adverse events occurred in our cohort followed up for a mean time of 547 days. Of the 20 subjects who remained in the study, 3 (15.0%) developed AD, suggesting a protective effect when compared with historical controls. Skin barrier measurements remained within ranges seen in normal-appearing skin.

LIMITATIONS

No conclusions regarding efficacy can be made without a control group.

CONCLUSIONS

Skin barrier repair from birth represents a novel and feasible approach to AD prevention. Further studies are warranted to determine the efficacy of this approach.

Quantitative risk assessment of contact sensitization: clinical data to assess utility of the model

BACKGROUND

Contact hypersensitivity quantitative risk assessment (QRA) for fragrance ingredients is being used to establish new international standards for all fragrance ingredients that are potential skin sensitizers.

OBJECTIVE

The objective was to evaluate the retrospective clinical data on three fragrance ingredients in order to provide a practical assessment of the predictive value of the QRA approach. It is important to have data to assess that the methodology provides a robust approach for primary prevention of contact sensitization induction for fragrance ingredients identified as potential sensitizers.

METHODS

This article reviews clinical data for three fragrance ingredients-cinnamic aldehyde, citral, and isoeugenol-to assess the utility of the QRA approach for fragrance ingredients.

RESULTS

This assessment suggests that had the QRA approach been available at the time standards were established for these fragrance ingredients, the clinical response might have been noticeably improved. Prospectively, with the establishment of QRA-derived standards, there should be a continued downward trend in patch test-positive rates for cinnamic aldehyde, citral, and isoeugenol over time.

CONCLUSION

While it is recognized that the availability of retrospective data is limited, a longitudinal review of these data gives confidence that the QRA approach should be an effective tool for primary prevention. This study also highlights the importance of continued active monitoring of clinical patch-test data for fragrance ingredients.