The allergic sensitization in infants with atopic eczema from different countries

Allergy-associated biomarkers in early life identified by Omics techniques

The prevalence and severity of allergic diseases have increased over the last 30 years. Understanding the mechanisms responsible for these diseases is a major challenge in current allergology, as it is crucial for the transition towards precision medicine, which encompasses predictive, preventive, and personalized strategies. The urge to identify predictive biomarkers of allergy at early stages of life is crucial, especially in the context of major allergic diseases such as food allergy and atopic dermatitis. Identifying these biomarkers could enhance our understanding of the immature immune responses, improve allergy handling at early ages and pave the way for preventive and therapeutic approaches. This minireview aims to explore the relevance of three biomarker categories (proteome, microbiome, and metabolome) in early life. First, levels of some proteins emerge as potential indicators of mucosal health and metabolic status in certain allergic diseases. Second, bacterial taxonomy provides insight into the composition of the microbiota through high-throughput sequencing methods. Finally, metabolites, representing the end products of bacterial and host metabolic activity, serve as early indicators of changes in microbiota and host metabolism. This information could help to develop an extensive identification of biomarkers in AD and FA and their potential in translational personalized medicine in early life.

The Impact of Climate Change on the Sporulation of Atmospheric Fungi

The U.S. Global Change Research Program, Fourth National Climate Assessment reports that it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. There are no convincing alternative explanations supported by observational evidence.

Management of atopic dermatitis by pediatricians: A French national survey-based study

PURPOSE

Atopic dermatitis (AD) is a chronic skin disease affecting 10% of children in Europe. The treatment of AD is well codified; however, a gap sometimes exists between recommendations and medical practice. The objective of this study was to assess the practice of French pediatricians regarding the management of AD.

METHODS

We conducted a national practice survey from September 2021 to October 2021, using an online questionnaire emailed to pediatric physicians.

RESULTS

A total of 83 pediatricians from 33 different departments responded to the survey. The clinical features of AD were known by the majority of pediatricians, but 15 (18%) found the diagnosis difficult to establish. All pediatricians prescribed daily applications of emollients and 78 (94%) prescribed topical corticosteroids (TCS) during AD flares, but misuses remained: only 29 (35%) pediatricians prescribed TCS when eczema (even if minimal) appeared and 43 (52%) did so at the onset of pruritus, while 45 (54%) prescribed them for extensive or disabling eczema, and 53 (64%) when eczema persisted after an initial treatment with emollients. Regarding diet, 12 (14%) pediatricians recommended a diet low on or free of cow milk, 10 (12%) systematically referred children with AD to an allergist, and 20 (24%) delayed food diversification.

CONCLUSION

Despite improvements in AD management by French pediatricians in the past 15 years, barriers to its appropriate management still persist, including the misuse of TCS and inappropriate diets.

Subtypes of atopic dermatitis: From phenotype to endotype

Atopic dermatitis (AD) is a heterogenous disorder and can be classified into different types. Stratification of subtypes may enable personalized medicine approaches. AD can be categorized into the IgE-high, extrinsic subtype and the IgE-normal, intrinsic subtype. While extrinsic AD is the major subtype possessing skin barrier impairment (high incidence of filaggrin mutations), intrinsic AD occupies about 20% of AD with female dominance and preserved barrier. Extrinsic AD exhibits protein allergy and food allergy, but intrinsic AD shows metal allergy possibly in association with suprabasin deficiency. In particular, accumulated knowledge of food allergy has more clearly characterized extrinsic AD. European American (EA) and Asian AD subtypes have been also proposed. Asian patients with AD are characterized by a unique blended immune dysregulation and barrier feature phenotype between EA patients with AD and those with psoriasis. In another ethnic study, filaggrin loss-of-function mutations are not prevalent in African American patients with AD, and Th1/Th17 attenuation and Th2/Th22 skewing were seen in these patients. Recent endotype classification provides new insights for AD and other allergic disorders. Endotype is defined as the molecular mechanisms underlying the visible features/phenotype. Endotype repertoire harbors activation of type 2 cytokines, type 1 cytokines, and IL-17/IL-22, impairment of epidermal barrier, and abnormalities of intercellular lipids. Classification of endotype has been attempted with serum markers. These lines of evidence indicate a need for personalized or precision medicine appropriate for each subtype of AD.

Extract and molecular-based early infant sensitization and associated factors-A PreventADALL study

BACKGROUND

More knowledge about sensitization patterns in early infancy, including impact of molecular allergology, is needed to help predict future allergy development more accurately.

OBJECTIVE

We aimed to determine the prevalence and patterns of allergic sensitization at 3 months of age, and explore possible associated factors.

METHODS

From the Scandinavian antenatally recruited PreventADALL mother-child cohort, we included 1110 3-month infants with available serum. Sensitization was defined as s-IgE of ≥0.1 kU_A /L by Phadiatop Infant^® (ThermoFisher Scientific) including birch, cat, grass, dog, milk, egg, peanut and wheat. Further ImmunoCAP analyses to ovomucoid, casein, Ara h 1-3, omega-5-gliadin were performed in food extract s-IgE-positive children. Maternal sensitization was defined as s-IgE ≥ 0.35 kU_A /L to Phadiatop^® (inhalant allergen mix) and/or Fx5 (food allergen mix) at 18-week pregnancy.

RESULTS

Overall 79 (7.3%) infants had specific sensitization, many with low s-IgE-levels (IQR 0.16-0.81 kU_A /L), with 78 being sensitized to food extract allergens; 41 to egg, 27 to milk, 10 to peanut, and 25 to wheat. A total of 62/78 were further analysed, 18 (29%) had s-IgE to ovomucoid, casein, Ara h 1-3 and/or omega-5-gliadin. Eight infants (0.7%) were sensitized to inhalant allergens. Maternal sensitization to food allergens was associated with infant sensitization, odds ratio 3.64 (95% CI 1.53-8.68).

CONCLUSION

Already at 3 months of age, 7% were sensitized to food, mostly without detectable s-IgE to food allergen molecules, and <1% to inhalant allergens. Maternal food sensitization was associated with infants' sensitization.

Cytokines and apoptosis in atopic dermatitis

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease. AD affects 10-20% of children worldwide and persists into adulthood in a minority of cases, affecting approximately 2-3% of the adult population, with an increased prevalence over the past decades in developed countries. Atopy is a genetic tendency to overproduce IgE class antibodies in response to common antigens found in the environment. Concurrence of different atopy such as allergic rhinitis or asthma in children with AD is estimated at 80%. AD is characterized by a vicious cycle of an allergic immune response. The emerging picture of the AD is a complex disorder with barrier dysfunction, immunological, genetic and environmental factors all playing key roles. Patients with severe or persistent disease and their families experience significant impairment in their quality of life, and in addition, AD places a heavy economic burden on society as a whole. Pathogenesis, the role of the epidermal barrier, mechanisms of cells apoptosis, the role of T cells and cytokines in AD are discussed in this article.

IgE-dependent sensitization to tropho- and aeroallergens with regard to age, sex and birth season of children and adolescents living in the north-eastern region of Poland

Introduction

A small number of studies concern trophoallergens and aeroallergens sensitization in the developmental age population in Poland. Only a few studies describe the role of selected factors determining the frequency and type of IgE-dependent sensitization in this population.

Aim

To assess the rate of sensitization to chosen tropho- and aeroallergens in the group of sensitized patients living in the north-eastern region of Poland with regard to age, sex and birth season.

Material and methods

Skin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to this study between 1998 and 2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents.

Results

Significant results were as follows: sensitization was more common in boys (41.9%) than in girls (35.7%); the highest percentage of sensitized patients was observed in the group of children aged 13–18 years (45.0%) as compared to the group of children up to 3 years old (the lowest 33.1%). The highest percentage of sensitized patients was observed among children born during winter (41.3%), the lowest among children born in autumn (36.8%).

Conclusions

The assessment of sensitization to chosen trophoallergens and airborne allergens should include the role of age, sex and birth season of the diagnosed patient.

Food Hypersensitivity in Children Aged 0-3 Years of the Lviv Region in Ukraine: A Cross-Sectional Study

Aim: To determine the prevalence and to estimate factors associated with food hypersensitivity in young children of the Lviv region in Ukraine. Methods: A prospective cross-sectional survey study was conducted between 2016 and 2017 in the Lviv region of Ukraine. A specially designed questionnaire about food hypersensitivity of young children developed and validated by M. J. Flokstra-de Blok was used after translation into the Ukrainian language. The questionnaire included 34 questions, grouped into general and detailed information. Parents of children aged 0-3 years were asked to complete the questionnaire at pre-schools and medical institutions. Results: Among 4,500 distributed questionnaires, 3,214 (71%) were completed and processed. Parents reported that 25% of their young children had food hypersensitivity. According to the survey the most common agents involved in food hypersensitivity in young children were cow's milk (34%), egg (28%), and wheat (24%). Hypersensitivity to milk occurred in 50% of children in the age group of 1-2 years. Regional differences associated with food hypersensitivity were also found. Namely, in the Carpathians, there was more hypersensitivity to fish (27%) and honey (22%) than in other regions, while hypersensitivity to soy was detected mostly in Lviv City residents (8.5%). Unknown causes of food hypersensitivity were highly reported (34%) in the Carpathians. Conclusion: Prevalence and some distinctiveness of food hypersensitivity revealed in four geographic and climate zones as well as in Lviv City have a considerable practical use for formulation of recommendations for children with food hypersensitivity.

Physiopathologie de la dermatite atopique et des autres maladies atopiques : une approche globale est-elle possible ?

Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease occurs: atopic dermatitis, food allergy, atopic asthma and allergic rhinitis and conjunctivitis. Whereas the classical "atopic march" is increasingly challenged through epidemiological studies, type-2 cellular inflammation is a characteristic shared by the atopic diseases. This inflammation can be innate (non-specific: eosinophils, mast cells, dendritic cells, innate lymphoid cells [ILC]), or adaptive (antigen-specific, involving T cells). Interleukins (IL-)4, 5 and 13 are major actors of type-2 inflammation and are mainly produced by ILC and T cells. The efficacy of treatments targeting these type-2 cytokines highlight the importance of type-2 inflammation in atopic diseases. However, several patients do not respond to type-2 targeting treatments, highlighting the presence of other actors in pathophysiology of atopic diseases: alteration of epithelial barrier, IgE-mediated allergic responses, type-17 inflammation. Thus, the term "endotype" can illustrate this diversity in pathophysiology. Finally, a global approach of atopic diseases, as type-2 inflammatory diseases, is fundamental, but not sufficient. An approach by endotype is advisable, in a personalized medicine perspective. © 2020 Elsevier Masson SAS. All rights reserved.

Histoire naturelle de la dermatite atopique

Atopic dermatitis (AD) is a common frequent chronic inflammatory skin disease which begins frequently in infancy. The clinical expression of AD is a recurrent eczema on a dry skin. AD is a multifactorial disease characterized by two linked abnormalities: a skin barrier defect and a cellular inflammation, with type-2 main components. However, the pathophysiology of AD is not as simple as this description looks like. In this review, we will present a synthesis of current knowledge on natural history of AD and the involved factors, in order to clarify AD care. The evolution of AD is associated with many atopic comorbidities, following the "atopic march" scheme: IgE-mediated food allergy, allergic asthma and rhinitis occurring classically after AD. In fact, this is rarely the case, but the atopic march seems to be associated with AD severity. AD has also many neuropsychological complications which are essential to be detected. Other factors could influence the natural history of AD: genetic mutations on different genes (proteins of skin barrier, innate and adaptive immunity pathways), skin dysbiosis with colonization by Staphylococcus aureus, sensitization against environmental proteins. AD treatment is based on the restauration of the skin barrier using emollients and on anti-inflammatory drugs (notably topical corticosteroids) during the inflammatory flares. It is not recommended to treat the skin colonization by S. aureus, excepted in case of skin infection. The probiotics have no efficiency as curative treatment of AD, but could have an interest for the primary prevention, especially in at-risk populations. © 2019 Elsevier Masson SAS. All rights reserved.

Immunoglobulin E-Mediated Food Allergies Differ in East Mediterranean Children Aged 0-2 Years

OBJECTIVE

Precise diagnosis of allergy requires knowledge of the population's food allergy (FA) spectrum and predictors.

METHODS

Medical charts of Turkish children aged 0-2 years with FA and/or atopic dermatitis (AD) were reviewed.

RESULTS

A total of 1,389 patients, 912 with FA and 1,140 with AD, were included. In the FA group, the most frequently diagnosed FAs were egg white (75.9%), cow's milk (55.7%), tree nuts (31.5%) and sesame (20.6%). The detection of FA in 99% of children with any kind of FA necessitate testing with egg white, cow's milk, hazelnut, sesame, walnut, cashew, and pistachio. In the FA group, 72.7 and 56.8% had AD and multiple FA respectively. Multiple FA (56.8 vs. 49.8%) and hen's egg allergy (85.5 vs. 50.2%, p < 0.005) were more common and cow's milk allergy (51.4 vs. 67.1%, p < 0.005) less common in the AD subgroup of the FA group than in the non-AD subgroup. Multiple FA likelihood increases parallel to the severity of AD (p < 0.05). In the AD group, 58.2% had an immunoglobulin E-mediated FA. The risk of concomitant FA increased as the age at symptom onset of AD decreased (OR 0.800 [95% CI 0.731-0.875]; p < 0.001) and the severity of AD increased (OR 2.350 [95% CI 1.898-2.911]; p < 0.001).

CONCLUSION

Although severe and early-onset AD is a predictor of the presence and magnitude of FA in infancy, the spectrum of FA is a reflection of cultural characteristics. The clinical presentations of both AD and FA may in fact be an expression of the extent of the immune dysregulation underlying atopy and allergy.

Clec10a regulates mite-induced dermatitis

House dust mite (HDM) is a major allergen that causes allergic diseases such as atopic dermatitis. However, the regulatory mechanisms of HDM-induced immune responses are incompletely understood. NC/Nga mice are an inbred strain that is more susceptible to HDM and develops more severe dermatitis than other strains. Using whole-exome sequencing, we found that NC/Nga mice carry a stop-gain mutation inClec10a, which encodes a C-type lectin receptor, Clec10a (MGL1/CD301a). The repair of this gene mutation using the CRISPR-Cas9 system ameliorated HDM-induced dermatitis, indicating that the Clec10a mutation is responsible for hypersensitivity to HDM in NC/Nga mice. Similarly,Clec10a−/−mice on the C57BL/6J background showed exacerbated HDM-induced dermatitis. Clec10a expressed on skin macrophages inhibits HDM-induced Toll-like receptor 4 (TLR4)–mediated inflammatory cytokine production through the inhibitory immunoreceptor tyrosine activating motif in its cytoplasmic portion. We identified asialoglycoprotein receptor 1 (Asgr1) as a functional homolog of mouse Clec10a in humans. Moreover, we found that a mucin-like molecule in HDM is a ligand for mouse Clec10a and human Asgr1. Skin application of the ligand ameliorated a TLR4 ligand-induced dermatitis in mice. Our findings suggest that Clec10a in mice and Asgr1 in humans play an important role in skin homeostasis against inflammation associated with HDM-induced dermatitis.

Influence of Atopic Dermatitis on Cow's Milk Allergy in Children

Background and Objectives: Cow’s milk protein allergy (CMA) is the most common allergy in children. The natural history of CMA is generally favorable and the majority of children reach tolerance during childhood, even if studies show variable results. Atopic dermatitis (AD) is a complex disease from an immunological point of view. It is characterized by an impaired skin barrier function and is often the first clinical manifestation of the so-called “atopic march”. The aim of our study is to evaluate, in a cohort of children with CMA, if the presence of AD in the first months of life can influence the atopic status of patients, the tolerance acquisition to cow’s milk, the level of specific IgE (sIgE), and the sensitization towards food and/or inhalant allergens. Materials and Methods: We enrolled 100 children with a diagnosis of CMA referred to our Pediatric Allergology Unit, aged 1–24 months at the time of the first visit. Results: 71 children had AD and 29 did not. The mean follow-up was 5.28 years. The CMA manifestations were mainly cutaneous, especially in children with AD (91.6% vs. 51.7%; P < 0.001). Patients with AD showed higher rates of polysensitization to foods and higher levels of both total IgE and sIgE for milk, casein, wheat, peanuts, and cat dander at different ages when compared to patients without AD. We analyzed the presence of IgE sensitization for the main foods and inhalants at various ages in the two groups of patients: a statistically significant difference emerged in the two groups of patients for milk, yolk and egg white, hazelnut, peanuts, soybean, grass pollen and cat dander. Meanwhile, we did not find significant differences in terms of tolerance acquisition toward cow’s milk, which was nonetheless reached around 5 years of age in 61% of patients. The level of cow’s milk sIgE at the age of 5 years was significantly higher in the group of patients who did not acquire tolerance (38.38 vs. 5.22 kU/L; P < 0.0001). Conclusions: An early barrier deficiency appears to promote the development of allergic sensitization, but does not seem to influence the acquisition of tolerance.

IgE testing can predict food allergy status in patients with moderate to severe atopic dermatitis

BACKGROUND

Diagnosing food allergy in patients with atopic dermatitis (AD) is complicated by their high rate of asymptomatic sensitization to foods, which can lead to misdiagnosis and unnecessary food avoidance.

OBJECTIVE

We sought to determine whether food-specific (sIgE) or component immunoglobulin (Ig) E levels could predict allergic status in patients with moderate to severe AD and elevated total IgE.

METHODS

Seventy-eight children (median age, 10.7 years) with moderate to severe AD were assessed for a history of clinical reactivity to milk, egg, peanut, wheat, and soy. The IgE levels for each food and its components were determined by ImmunoCAP. The level and pattern of IgE reactivity to each food and its components, and their ratio to total IgE, were compared between subjects who were allergic and tolerant to each food.

RESULTS

Ninety-one percent of subjects were sensitized, and 51% reported allergic reactivity to at least 1 of the 5 most common food allergens. Allergy to milk, egg, and peanut were most common, and IgE levels to each of these foods were significantly higher in the allergic group. Component IgEs most associated with milk, egg, and peanut allergy were Bos d8, Gal d1, and Ara h2, respectively. The ratio of sIgE to total IgE offered no advantage to sIgE alone in predicting allergy.

CONCLUSION

Specific IgE levels and the pattern of IgE reactivity to food components can distinguish AD subjects allergic vs tolerant to the major food allergens and may therefore be helpful in guiding the clinical management of these patients.

Cytokine Gene Polymorphisms in Saudi Patients With Atopic Dermatitis: A Case-Control Study

The cause of atopic dermatitis (AD) is multifactorial and a number of genes including cytokines have been involved. We genotyped 315 subjects for polymorphisms in TNF-α and TNF-β and IL-10 genes. Patients had significantly higher frequency of GA genotype of TNF-α (−308 G/A) than healthy controls. Patients with AD and controls had similar distribution of A and G alleles. Genotype AA was found in 7.11% of controls while completely absent in cases. The frequencies of genotypes GG and AA of TNF-β (+252 A/G) polymorphism were higher whereas the frequency of genotype GA was significantly lower in patients than the controls. The frequencies of genotypes GG and AA of IL-10 (1082 G/A) polymorphism were significantly increased whereas genotype GA was decreased in patients than the controls. It is concluded that TNF-α (−308 G/A), TNF-β (+252 A/G), and IL-10 (−1082 G/A) polymorphisms are linked with the susceptibility of AD in Saudis and can be a risk factor.

Component resolved diagnostic study of cow's milk allergy in infants and young children in northern China

BACKGROUND

Increasing dairy consumption in China has been accompanied by rising incidence of milk allergy. Here we analyzed profiles of specific immunoglobulin E (sIgE) against cow's milk proteins, and assessed their value for milk allergy diagnosis among infants and young children from northern China.

METHODS

Sera collected from 48 patients with milk allergy and 27 negative control subjects was analyzed by enzyme-linked immunosorbent assay to measure sIgE to α-lactalbumin (Bos d 4), β-lactoglobulin (Bos d 5), α-casein (Bos d 9), β-casein (Bos d 11), and κ-casein (Bos d 12).

RESULTS

Among milk-allergic individuals, most were sensitized to at least one milk protein; about half were sensitized to Bos d 5, Bos d 9, Bos d 11 and Bos d 12, respectively, while few had positive serum sIgE against Bos d 4. Bos d 12 sIgE had the largest area under curve (AUC) (0.878; 95% CI, 0.800-0.957) and thus showed the best diagnostic performance in discriminating between milk-allergic and non-milk allergic patients, with a sensitivity of 92.6% and specificity of 72.9% using a statistically optimal cut-off value (OD_450nm, 0.191). The combinations of Bos d 5 + Bos d 12 showed an AUC of 0.926, which was larger than for any individual components.

CONCLUSIONS

Our results revealed inter-individual variation in the sensitization to different milk allergen component. Bos d 12 sIgE showed best performance in diagnosing milk allergy. Milk allergy diagnostic accuracy was further improved using combinations of milk allergen components by application of ROC curves based on logistic regression.

New insights into the phenotypes of atopic dermatitis linked with allergies and asthma in children: An overview

Atopic dermatitis (AD) is a complex disease with multiple causes and complex mechanistic pathways according to age of onset, severity of the illness, ethnic modifiers, response to therapy and triggers. A group of difficult-to-manage patients characterized by early-onset AD and severe lifelong disease associated with allergic asthma and/or food allergy (FA) has been identified. In this study, we focus on these severe phenotypes, analysing their links with other atopic comorbidities, and taking into account the results from recent cohort studies and meta-analyses. The main hypothesis that is currently proposed to explain the onset of allergic diseases is an epithelial barrier defect. Thus, the atopic march could correspond to an epithelial dysfunction, self-sustained by a secondary allergenic sensitization, explaining the transition from AD to allergic asthma. Furthermore, AD severity seems to be a risk factor for associated FA. Results from population-based, birth and patient cohorts show that early-onset and severe AD, male gender, parental history of asthma, and early and multiple sensitizations are risk factors leading to the atopic march and the development of asthma. The importance of environmental factors should be recognized in these high-risk children and prevention programs adapted accordingly. Effective targeted therapies to restore both barrier function and to control inflammation are necessary; early emollient therapy is an important approach to prevent AD in high-risk children. Clinicians should also keep in mind the specific risk of atopic comorbidities in case of filaggrin loss-of-function mutations and the rare phenotypes of orphan syndromes due to heritable mutations in skin barrier components.

A 8-year population-based cohort study of irritable bowel syndrome in childhood with history of atopic dermatitis

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder affecting a large number of people worldwide. Based on the concept of central sensitization, we conducted a population-based cohort analysis to investigate the risk of IBS in children with atopic dermatitis (AD) as one of the first steps in the atopic march. From 2000 to 2007, 1 20 014 children with newly diagnosed AD and 1 20 014 randomly selected non-AD controls were included in the study. By the end of 2008, incidences of IBS in both cohorts and the AD cohort to non-AD cohort hazard ratios (HRs) and CIs were measured. The incidence of IBS during the study period was 1.45-fold greater (95% CI: 1.32 to 1.59) in the AD cohort than in the non-AD cohort (18.8 vs 12.9 per 10 000 person-years). The AD to non-AD HR of IBS was greater for girls (1.60, 95% CI: 1.39 to 1.85) and children≥12 years (1.59, 95% CI: 1.23 to 2.05). The HR of IBS in AD children increased from 0.84 (95% CI: 0.75 to 0.94) for those with ≤3 AD related visits to 16.7 (95% CI: 14.7 to 18.9) for those with >5 visits (P<0.0001, by the trend test). AD children had a greater risk of developing IBS. Further research is needed to clarify the role of allergy in the pathogenesis of IBS.

Expression of IL-22 in the Skin Causes Th2-Biased Immunity, Epidermal Barrier Dysfunction, and Pruritus via Stimulating Epithelial Th2 Cytokines and the GRP Pathway

Increased expression of Th22 cytokine IL-22 is a characteristic finding in atopic dermatitis (AD). However, the specific role of IL-22 in the pathogenesis of AD in vivo has yet to be elucidated. Consistent with observations in human AD, IL-22 was significantly increased in the AD skin of mice after epicutaneous sensitization to house dust mite allergen. Utilizing a skin-specific inducible transgenic system, we show in the present study that expression of IL-22 in the skin of mice caused an AD-like phenotype characterized by chronic pruritic dermatitis associated with Th2-biased local and systemic immune responses, downregulation of epidermal differentiation complex genes, and enhanced dermatitis upon epicutaneous allergen exposure. IL-22 potently induced the expression of gastrin-releasing peptide (GRP), a neuropeptide pruritogen, in dermal immune cells and sensory afferents and in their skin-innervating sensory neurons. IL-22 also differentially upregulated the expression of GRP receptor (GRPR) on keratinocytes of AD skin. The number of GRP+ cells in the skin correlated with the AD severity and the intensity of pruritus. IL-22 directly upregulated the expression of epithelial-derived type 2 cytokines (thymic stromal lymphopoietin and IL-33) and GRP in primary keratinocytes. Furthermore, GRP not only strongly induced thymic stromal lymphopoietin but it also increased the expression of IL-33 and GRPR synergistically with IL-22. Importantly, we found that the expression of GRP was strikingly increased in the skin of patients with AD. These results indicate that IL-22 plays important pathogenic roles in the initiation and development of AD, in part through inducing keratinocyte production of type 2 cytokines and activation of the GRP/GRPR pathway.

Atopic Eczema: Genetic Associations and Potential Links to Developmental Exposures

Atopic eczema (AE), or atopic dermatitis (AD), is a common inflammatory skin disease with a disrupted epidermal barrier and an allergic immune response. AD/AE is prominently characterized by a symptomatic itch and transient skin lesions. Infants compose a significant percentage affected. Two models have been proposed to explain AD/AE skin pathology: the gut microbiome-focused inside-outside model and the outside-inside model concentrating on the disrupted skin barrier/skin microbiome. Gene disruptions contributing to epidermal structure, as well as those in immune system genes, are implicated. Over 30 genes have been linked to AD/AE with Flg and Tmem79/Matt alterations being common. Other linked disruptions are in the interleukin-1 family of cytokines/receptors and the TH2 gene family of cytokines. Inheritable epigenetic modifications of the genes or associated proteins may also be involved. Skin barrier disruption and the allergic immune response have been the main foci in mechanistic studies of AD/AE, but the role of the environment is becoming more apparent. Thus, an examination of in utero exposures could be very helpful in understanding the heterogeneity of AD/AE. Although research is limited, there is evidence that developmental exposure to environmental tobacco smoke or phthalates may impact disease. Management for AD/AE includes topical corticosteroids and calcineurin inhibitors, which safely facilitate improvements in select individuals. Disease heterogeneity warrants continued research not only into elucidating disease mechanism(s), via identification of contributing genetic alterations, but also research to understand how/when these genetic alterations occur. This may lead to the cure that those affected by AD/AE eagerly await.

Sensitization to common allergens among patients with allergies in major Iranian cities: a systematic review and meta-analysis

Various allergens are implicated in the pathogenesis of allergic diseases in different regions. This study attempted to identify the most common allergens among patients with allergies based on the results of skin prick tests in different parts of Iran. Relevant studies conducted from 2000 to 2016 were identified from the MEDLINE database. Six common groups of allergen types, including animal, cockroach, food, fungus, house dust mite, and pollen were considered. Subgroup analysis was performed to determine the prevalence of each type of allergen. The Egger test was used to assess publication bias. We included 44 studies in this meta-analysis. The overall prevalence of positive skin test results for at least one allergen was estimated to be 59% in patients with allergies in various parts of Iran. The number of patients was 11,646 (56% male and 44% female), with a mean age of 17.46±11.12 years. The most common allergen sources were pollen (47.0%), mites (35.2%), and food (15.3%). The prevalence of sensitization to food and cockroach allergens among children was greater than among adults. Pollen is the most common allergen sensitization in cities of Iran with a warm and dry climate; however, sensitization to house dust mites is predominant in northern and southern coastal areas of Iran.

Assessment of IgE-mediated food allergies in children with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is an inflammatory disease of the skin, which is characterised by a chronic relapsing course.

AIM

The aim of the study was to assign the prevalence of clinically active food allergies among a group of children between 3 months and 7 years of age, with AD.

METHODS

Eighty-eight children with AD were screened for specific IgE antibodies to food proteins. All patients with AD and specific IgE antibodies to food proteins were subjected to Oral Food Challenges (OFCs) with the relevant foods.

RESULTS

Food-sensitised patients with moderate levels of sIgE had clinically active food allergy to milk (39.28%) and egg (42.34%) on the basis of positive OFCs. High IgE and eosinophilia had a prevalence of almost 80% and 25%, regardless of concomitant food sensitisation and disease severity.

CONCLUSIONS

In this study, clinically active food allergies were recognised in 26.13% of children with AD. Nevertheless, no association was confirmed between food sensitisation and AD severity. High IgE and peripheral eosinophilia have not been found more prevalent among children with severe AD nor among children with food sensitisation. Infants and younger children with AD should be screened for an underlying food allergy, regardless of disease severity.

A new framework for the interpretation of IgE sensitization tests

IgE sensitization tests, such as skin prick testing and serum-specific IgE, have been used to diagnose IgE-mediated clinical allergy for many years. Their prime drawback is that they detect sensitization which is only loosely related to clinical allergy. Many patients therefore require provocation tests to make a definitive diagnosis; these are often expensive and potentially associated with severe reactions. The likelihood of clinical allergy can be semi-quantified from an IgE sensitization test results. This relationship varies though according to the patients' age, ethnicity, nature of the putative allergic reaction and coexisting clinical diseases such as eczema. The likelihood of clinical allergy can be more precisely estimated from an IgE sensitization test result, by taking into account the patient's presenting features (pretest probability). The presence of each of these patient-specific factors may mean that a patient is more or less likely to have clinical allergy with a given test result (post-test probability). We present two approaches to include pretest probabilities in the interpretation of results. These approaches are currently limited by a lack of data to allow us to derive pretest probabilities for diverse setting, regions and allergens. Also, cofactors, such as exercise, may be necessary for exposure to an allergen to result in an allergic reaction in specific IgE-positive patients. The diagnosis of IgE-mediated allergy is now being aided by the introduction of allergen component testing which may identify clinically relevant sensitization. Other approaches are in development with basophil activation testing being closest to clinical application.

Pilot study: assessing the clinical diagnosis of allergy in atopic children using a microarray assay in addition to skin prick testing and serum specific IgE

Background

Children with atopic dermatitis (AD) are at risk of developing allergy. Alongside clinical history, testing modalities include skin prick tests (SPT), specific immunoglobulin-E (sp-IgE) and recently, microarray assays. The aim of this pilot study was to assess current tests and the ISAC sIgE-112 system in the diagnosis of food and aeroallergen allergy.

Methods

Children aged 0–11 years with moderate to severe AD were included. An initial allergy assessment including clinical history, SPT and sp-IgE was performed to determine food and aeroallergen sensitization. A second independent clinical assessment using the same information given to the first assessor and ISAC test results for food and aeroallergen sensitization was also made for each participant. The results from both were compared.

Results

30 children [mean age 3.91 years (SD 3.3)] were included; 53.3 and 46.7 % had moderate and severe AD, respectively. Sp-IgE tests had a higher percentage of positive results compared to SPT and ISAC tests for common allergens. There was a significant difference between the three tests in detecting aeroallergen sensitization (p = 0.038), especially between sp-IgE and ISAC tests, but no significant difference between the tests for food allergen sensitization. There was good agreement between the two assessors; 70 % of the children had a change in diagnosis, with 60 % having at least one diagnosis added and 40 % having at least one diagnosis removed.

Conclusions

There is a role for the use of ISAC testing in diagnosing sensitization and allergy in children with AD as it leads to a change in diagnosis for many patients. Further work is required to assess its clinical and cost effectiveness.

Electronic supplementary material

The online version of this article (doi:10.1186/s12948-016-0046-z) contains supplementary material, which is available to authorized users.

Debates in allergy medicine: Specific immunotherapy in children with atopic dermatitis, the "con" view

Atopic dermatitis (AD) is a common chronic skin condition in children that has a proven association with other atopic conditions and allergies. These associations, like the general pathophysiology of AD, are complex and not fully understood. While there is evidence for the efficacy of specific immunotherapy (SIT) in pediatric asthma and allergic rhinitis (AR), there is a lack of strong data to support its use in AD. IgE has been shown to be elevated in many patients with AD, but it is an unreliable biomarker due to variability and great fluctuation over time, poor positive predictive value for clinically relevant allergy, and poor correlation with disease state. In spite of this, almost all studies of SIT use either positive skin prick testing (SPT) or serum specific IgE levels to guide therapy. Allergen avoidance, with some exceptions, is generally not effective at controlling AD in children. The few studies that have investigated the efficacy of SIT in children with AD have produced conflicting results, and a lack of reproducibility with a standard treatment protocol. Limited studies have shown clinical improvement in mild to moderate AD cases, but no effect on more severe patients. Uncontrolled studies are difficult to interpret, due to the natural history of remission or “outgrowing” of AD over time in many patients without specific interventions. Drawbacks to SIT include the length of treatment, poor compliance, cost, and potential side effect profile. The potential for misdirection of time and energy away from skin directed therapy could negatively impact on AD outcomes.

Atopic dermatitis

Atopic dermatitis (also known as atopic eczema) is a chronic inflammatory skin disease that is characterised by intense itching and recurrent eczematous lesions. Although it most often starts in infancy and affects two of ten children, it is also highly prevalent in adults. It is the leading non-fatal health burden attributable to skin diseases, inflicts a substantial psychosocial burden on patients and their relatives, and increases the risk of food allergy, asthma, allergic rhinitis, other immune-mediated inflammatory diseases, and mental health disorders. Originally regarded as a childhood disorder mediated by an imbalance towards a T-helper-2 response and exaggerated IgE responses to allergens, it is now recognised as a lifelong disposition with variable clinical manifestations and expressivity, in which defects of the epidermal barrier are central. Present prevention and treatment focus on restoration of epidermal barrier function, which is best achieved through the use of emollients. Topical corticosteroids are still the first-line therapy for acute flares, but they are also used proactively along with topical calcineurin inhibitors to maintain remission. Non-specific immunosuppressive drugs are used in severe refractory cases, but targeted disease-modifying drugs are being developed. We need to improve understanding of the heterogeneity of the disease and its subtypes, the role of atopy and autoimmunity, the mechanisms behind disease-associated itch, and the comparative effectiveness and safety of therapies.

Egg proteins as allergens and the effects of the food matrix and processing

Hen eggs are an important and inexpensive source of high-quality proteins in the human diet. Egg, either as a whole or its constituents (egg yolk and white), is a key ingredient in many food products by virtue of its nutritional value and unique functional properties, such as emulsifying, foaming, and gelling. Nevertheless, egg is also known because of its allergenic potential and, in fact, it is the second most frequent source of allergic reactions, particularly in children. This review deals with the structural or functional properties of egg proteins that make them strong allergens. Their ability to sensitize and/or elicit allergic reactions is linked to their resistance to gastroduodenal digestion, which ultimately allows them to interact with the intestinal mucosa where absorption occurs. The factors that affect protein digestibility, whether increasing it, decreasing it, or inducing a different proteolysis pattern, and their influence on their capacity to induce or trigger an allergic reaction are discussed. Special attention is paid to the effect of the food matrix and the processing practices on the capacity of egg proteins to modulate the immune response.

Sensitization to milk, egg and peanut from birth to 18 years: A longitudinal study of a cohort at risk of allergic disease

BACKGROUND

Longitudinal data on the natural history of food sensitization beyond early childhood are scarce. We aimed to investigate the natural history of milk, egg and peanut sensitization from infancy to 18 years and assess whether early food sensitization predicted adolescent food allergy.

METHODS

Sensitization to cow's milk, hen's egg and peanut was measured by skin prick testing at ages 6 months, 1, 2, 12 and 18 years in a high-risk allergy birth cohort (n = 620). Generalized additive models investigated interactions with sex, eczema and aeroallergen sensitization in infancy. Logistic regression assessed the relationships between early food sensitization and adolescent sensitization and probable food allergy up to 18 years.

RESULTS

The prevalence of egg and peanut sensitization peaked at 12 months, while milk sensitization peaked at both 1 and 12 years. Boys with early eczema had the highest prevalences of milk and egg sensitization throughout follow-ups. However, neither sex nor eczema influenced the prevalence of peanut sensitization over time. New onset food sensitization beyond the age of 2 was observed in 7% of participants. Food sensitization at 12 months was associated with increased risk of adolescent food sensitization and adolescent probable food allergy, with sensitization to more than one food allergen had the strongest predictor.

CONCLUSIONS

Food sensitization prevalence is highest in infancy and declines after 12 months of age. Boys with early-life eczema have the highest prevalence of milk and egg sensitization. Food sensitization at 12 months can predict children at greater risk of adolescent sensitization and probable food allergy at 12 and 18 years.

Assessment of pet exposure by self-report in epidemiological studies of allergy and asthma: a systematic review

OBJECTIVE

In epidemiological studies that aim to investigate the relationship between pet exposure and allergy/asthma, pet exposure is often ascertained by means of a questionnaire, but it is unclear which questionnaire items are used. The objective of this study was to systematically review self-reported pet exposure assessment in questionnaires used in epidemiological studies which explore the associations between pets and allergy/asthma.

METHODS

A systematic literature search was conducted in PubMed and papers were selected according to pre-specified eligibility criteria. The pet exposure questions used were classified within a framework including direct pet contact, indirect pet contact (e.g. through carers or grandparents) and avoidance behaviour. Authors were contacted when the questions used were not reported in detail.

RESULTS

Ninety-six full text papers were systematically reviewed. All studies assessed direct pet contact, but less than half (45%) explicitly assessed whether pets were allowed indoors. The vast majority of studies assessed both pet exposures during the first year of life and after the first year of life. The minority (13%) assessed whether pet(s) were kept at places regularly visited by the child and pet exposure in utero (15%). Even fewer studies assessed indirect contact to pets (n = 8) and avoidance behaviour (n = 10).

CONCLUSIONS

In epidemiological studies, the ascertainment of pet exposure through questionnaires appears to vary greatly. This variation might partly explain the inconsistent and contradictory results of the effects of pet exposure on the development of allergy and asthma.

Association of STAT6 genetic variants with childhood atopic dermatitis in Taiwanese population

BACKGROUND

Atopic dermatitis (AD) is the single most common allergic disease in children. STAT6 has been noted as a hub molecule in IL-4 mediated response and AD pathogenesis. However, the association between STAT6 genetic variants and childhood AD has never been thoroughly examined.

OBJECTIVE

We investigate the association between STAT6 genetic variants and childhood AD risk in Taiwanese population.

METHODS

We used data from the Han Chinese in Beijing genome panel of International HapMap Project and the Taiwan Children Health Study cohort to investigate the association of STAT6 genetic variants and childhood AD risks. Four tagged SNPs were selected from HapMap database and rs324011 was most significantly associated with childhood AD. Subsequently, deep sequencing around rs324011 and unconditional/conditional logistic models were applied.

RESULTS

rs324011 showed statistical significance for the occurrence of childhood AD (OR: 1.23; 95% CI: 1.01-1.51) and rs167769 showed borderline statistical significance (OR: 1.21; 95% CI: 0.99-1.49). Likelihood ratio tests revealed that haplotypes (rs167769/rs324011) were associated with childhood AD (global p=0.0018). T alleles of two STAT6 intron2 SNPs, rs324011 and rs167769, increased STAT6 promoter activity significantly in luciferase reporter assay.

CONCLUSION

T allele of rs324011 in STAT6 would increase the risk of AD occurrence in children. Haplotypes of rs324011/rs167769 were also significantly associated with childhood AD in Taiwanese population.

Mold allergens in respiratory allergy: from structure to therapy

Allergic reactions to fungi were described 300 years ago, but the importance of allergy to fungi has been underestimated for a long time. Allergens from fungi mainly cause respiratory and skin symptoms in sensitized patients. In this review, we will focus on fungi and fungal allergens involved in respiratory forms of allergy, such as allergic rhinitis and asthma. Fungi can act as indoor and outdoor respiratory allergen sources, and depending on climate conditions, the rates of sensitization in individuals attending allergy clinics range from 5% to 20%. Due to the poor quality of natural fungal allergen extracts, diagnosis of fungal allergy is hampered, and allergen-specific immunotherapy is rarely given. Several factors are responsible for the poor quality of natural fungal extracts, among which the influence of culture conditions on allergen contents. However, molecular cloning techniques have allowed us to isolate DNAs coding for fungal allergens and to produce a continuously growing panel of recombinant allergens for the diagnosis of fungal allergy. Moreover, technologies are now available for the preparation of recombinant and synthetic fungal allergen derivatives which can be used to develop safe vaccines for the treatment of fungal allergy.

Estimating the prevalence of aero-allergy and/or food allergy in infants, children and young people with moderate-to-severe atopic eczema/dermatitis in primary care: multi-centre, cross-sectional study

OBJECTIVE

We sought to determine the primary care-based prevalence of moderate-to-severe atopic eczema/dermatitis in children and to estimate what proportion had co-morbid aero-allergy and/or food allergy that was contributing to their atopic eczema/dermatitis.

DESIGN

Multi-centre, cross-sectional study.

PARTICIPANTS

Infants, children and young people aged between 0-17 years.

SETTING

Primary Care.

METHODS

General practice electronic health records were interrogated to identify children (0-17 years) with current moderate-to-severe atopic eczema/dermatitis. Eligible children were assessed by an allergy specialist nurse, this involving a detailed allergy history, examination and, if appropriate, measurement of total IgE and specific IgE to relevant aero-allergens and/or food allergens.

MAIN OUTCOME MEASURES

Prevalence of atopic eczema, moderate to severe atopic eczema, IgE-mediated atopic eczema.

RESULTS

We recruited eight practices, which together enrolled 16,877 children. Of these, 4331 (25.7%; 95% CI 25.0, 26.3) children had a recorded diagnosis of atopic eczema/dermatitis and 1316 (7.8%; 95% CI 7.4, 8.2) had treatment indicative of current moderate-to-severe atopic eczema/dermatitis. We recruited 159 children for clinical assessment, and complete data were available for 157. The clinical assessment revealed that 130/157 (82.8%) had no indication of IgE-mediated allergy contributing to their atopic eczema/dermatitis; the remaining 27/157 (17.2%; 95% CI 12.1, 23.9) were on clinical assessment considered to possibly have underlying IgE-mediated disease. Specific IgE tests were positive in 14/27 (51.9%; 95% CI 34.0, 69.3) children. Of the 14 children who tested positive, six (42.9%; 95% CI 21.4, 67.4) were positive to food allergens and six (42.9%; 95% CI 21.4, 67.4) to aero-allergens; the remaining two (14.3%; 95% CI 4.0, 40.0) were positive to both food and aero-allergens.

CONCLUSIONS

Although atopic eczema/dermatitis is a very common diagnosis in children in primary care, most appear to be relatively mild and/or transient. Only a small proportion of children had evidence of ongoing underlying IgE-mediated atopic eczema/dermatitis.

Establishing a cut-off for the serum levels of specific IgE to milk and its components for cow's milk allergy: results from a specific population

BACKGROUND

Cow's milk allergy diagnosis many times requires double-blind placebo-controlled food challenge (DBPCFC), which presents high accuracy but involves risks, specifically in infants and anaphylactic patients. The identification of the cut-off values for specific IgE to milk or its components would contribute to cow's milk allergy (CMA) diagnosis. The aim of this study was to compare discriminating concentration of a cow's milk specific IgE and its fractions (α-lactoalbumin, β-lactoglobulin, casein) in children for the CMA diagnosis.

METHODS

this study included 123 patients (M:F=1.3:1) median age at diagnosis=1.91 years, (3.5m to 13.21y) with CMA diagnosis via DBPCFC (n=26), proven anaphylaxis due to cow's milk (n=46) or a suggestive clinical history associated with a positive skin prick test (n=51) and open oral food challenge. The control group included 61 patients (1 male:1.1 female) ages ranging from 0.66 to 16.7 years (median=6.83 years). Receiver operator characteristics (ROC) curves were constructed to determine the best cut-offs that guarantees high specificity (>95%) for cow's milk and its components.

RESULTS

considering 98% specificity, cut-off points were: 3.06 kU/L for cow's milk, 2.06 kU/L for α-lactalbumin, 1.85 kU/L for β-lactoglobulin and 1.47kU/L for casein. The best ROC curve (area under the curve=0.929) was obtained evaluating cow's milk.

CONCLUSION

this study showed that the cut-off point detected for whole cow's milk revealed a better discriminatory capacity for CMA diagnosis without the necessity of the milk components testing.

Alpine climate treatment of atopic dermatitis: a systematic review

Climate therapy has been used for decades in the treatment of atopic dermatitis (AD), but evidence of its effectiveness has not yet been assessed systematically. A systematic literature search in Medline, Embase, and the Cochrane library was performed to identify all original studies concerning alpine climate treatment. The risk of bias of individual studies was assessed following the Cochrane Handbook, and level of evidence was rated using GRADE guidelines. Fifteen observational studies were included concerning 40 148 patients. Four studies concerning 2670 patients presented follow-up data over a period of 1 year. Disease activity decreased in the majority of patients during treatment (96% of n = 39 006) and 12-month follow-up (64% of n = 2670). Topical corticosteroid use could often be reduced or stopped during treatment (82% of n = 1178) and during 12-month follow-up (72% of n = 3008). Quality assessment showed serious study limitations, therefore resulting in a very low level of evidence for the described outcomes. Randomized controlled trials designed with a follow-up period including well-defined patient populations, detailed description and measurement of applied interventions during climate therapy and using validated outcomes including cost-effectiveness parameters, are required to improve the evidence for alpine climate therapy as an effective treatment for patients with AD.

Food allergy in Africa: myth or reality?

Food allergy has been traditionally perceived as being rare in Africa. However, the prevalence of other allergic manifestations such as asthma and atopic dermatitis continue to rise in the higher-income African countries. Since the food allergy epidemic in westernized countries has lagged behind that of allergic respiratory conditions, we hypothesize that food allergy is increasing in Africa. This article systematically reviews the evidence for food allergy in Africa, obtained through searching databases including PubMed, Medline, MD Consult, and scholarly Google. Articles are divided into categories based on strength of methodological diagnosis of food allergy. Information was found for 11 African countries: Botswana, Democratic Republic of Congo, Ghana, Kenya, Morocco, Mozambique, Nigeria, South Africa, Tanzania, Tunisia, and Zimbabwe. Most studies reflect sensitization to food or self-reported symptoms. However, a few studies had more stringent diagnostic testing that is convincing for food allergy, mostly conducted in South Africa. Apart from the foods that commonly cause allergy in westernized countries, other regionally significant or novel food allergens may include pineapple (Ghana), okra (Nigeria), and mopane worm (Botswana). Food allergy is definitely an emerging disease in Africa and resources need to be diverted to study, diagnose, treat, and prevent this important disease.

BSACI guideline for the diagnosis and management of cow's milk allergy

This guideline advises on the management of patients with cow's milk allergy. Cow's milk allergy presents in the first year of life with estimated population prevalence between 2% and 3%. The clinical manifestations of cow's milk allergy are very variable in type and severity making it the most difficult food allergy to diagnose. A careful age- and disease-specific history with relevant allergy tests including detection of milk-specific IgE (by skin prick test or serum assay), diagnostic elimination diet, and oral challenge will aid in diagnosis in most cases. Treatment is advice on cow's milk avoidance and suitable substitute milks. Cow's milk allergy often resolves. Reintroduction can be achieved by the graded exposure, either at home or supervised in hospital depending on severity, using a milk ladder. Where cow's milk allergy persists, novel treatment options may include oral tolerance induction, although most authors do not currently recommend it for routine clinical practice. Cow's milk allergy must be distinguished from primary lactose intolerance. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for clinicians in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking the panel of experts in the committee reached consensus. Grades of recommendation are shown throughout. The document encompasses epidemiology, natural history, clinical presentations, diagnosis, and treatment.

Increased risk of idiopathic nephrotic syndrome in children with atopic dermatitis

BACKGROUND

Clinical and immunological studies have consistently shown a relationship between atopic diathesis and idiopathic nephrotic syndrome (INS). However, no large population cohort study has yet to demonstrate the nature of the relationship between these disorders.

METHODS

Claims data from a random selection of children representing half of the insured population in Taiwan were examined. During the period from 1998 to 2007, we identified 192,295 children aged <18 years with newly diagnosed atopic dermatitis (AD) and 769,169 frequency-matched controls. Incidence of INS and hazard ratios (HRs) were calculated.

RESULTS

The AD cohort had a 2-fold higher overall incidence of INS than the non-AD cohort [7.20 vs. 3.60 per 100,000 person-years, respectively; 95 % confidence interval (CI) 1.50-2.66]. The HR for INS increased with age and was higher among females. The HR for INS was also higher in AD children with more medical visits per year, ranging from 0.94 for those having ≤3 visits to 38.6 for those having >6 visits (trend test P < 0.0001). In particular, the risk of INS clearly increased during the initial 5 years after AD onset.

CONCLUSIONS

Children with AD have a greater incidence and risk of developing INS and this risk increases with AD severity.

Specific IgG and IgA of common foods in Chinese children with eczema: friend or foe

BACKGROUND

Specific immunoglobulins G and A (IgG and IgA) for common food items have been extensively measured as surrogate markers of food allergy, and dietary avoidance based on the test results advocated.

AIM

We reviewed the prevalence of specific food IgG and IgA in children with eczema and evaluated outcome of dietary avoidance in these children.

METHODS

Specific immunoglobulins of 96 food items were measured for 30 consecutive atopic dermatitis (AD) patients and disease severity [SCORing atopic dermatitis (SCORAD) and Nottingham eczema severity score (NESS)], Children Dermatology Life Quality Index (CDLQI), skin hydration (SH), transepidermal water loss (TEWL), topical corticosteroid and oral antihistamine usage were evaluated. Twenty seven of these patients received dietary avoidance advice based on IgG and IgA data. General acceptability of treatment (GAT) was documented at the end of 3 months.

RESULTS

There were generally no correlations among levels of IgG or IgA of the 96 food items and disease severity, quality of life, SH or TEWL. Two-third patients reported very good or good and one-third reported fair or poor GAT following dietary avoidance advice. There was no difference in any clinical parameters between the two groups following dietary avoidance. Patient with lower sunflower seed IgA (p = 0.043), casein IgG (p = 0.041), milk IgG (p = 0.037) or whey IgG (p = 0.014) had improved SCORAD and objective SCORAD following dietary advice.

CONCLUSION

Children with AD are sensitized to many food allergens via IgG and IgA mechanisms. Levels of food IgG or IgA do not seem to correlate with any clinical parameters in AD. Subjectively, two third of patients accepted dietary manipulations as very good or good for their AD. Objectively, dietary avoidance had few clinical effects on the clinical parameters. Sensitization should not be generalized to mean allergy to common food.

Atopic dermatitis: optimizing the topical therapy

Goal. Determination of the skin microbiocenosis in patients with atopic dermatitis (AtD) and evaluation of the treatment efficacy for AtD patients using isoconazole nitrate and diflucortolone valerate. Materials and methods. The authors assessed skin microflora in 168 AtD patients. Skin scrapes were obtained for further microscopy, and inoculation tests were performed. As many as 59 secondary AtD patients were treated with a combination of isoconazole nitrate and diflucortolone valerate as well as methylprednisolone aceponate, drugs from the DARDIA line. The treatment efficacy was evaluated clinically based on the SCORAD index as well as skin microrelief assessed with the use of the Visioscan BW30 video camera. After the treatment with Travocort, the nature and degree of skin colonization with AtD microorganisms were also assessed. Results. The efficacy of topical administration of isoconazole nitrate and diflucortolone valerate as well as methylprednisolone aceponate, drugs from the DARDIA line, was confirmed for the treatment of secondary AtD patients. Conclusion. Making antibiotics and antimycotic agents a part of the complex therapy of secondary AtD patients seems to be expedient for eliminating pathogenic microorganisms.

Food hypersensitivity in patients with childhood atopic dermatitis in Korea

Background

It is well known that atopic dermatitis (AD) is related to food hypersensitivity, although its prevalence varies among several studies according to age group, severity, country, survey time, and test method.

Objective

To examine the prevalence and status of food hypersensitivity among childhood AD patients in Korea.

Methods

A total of 95 patients were enrolled in the study. The history of food hypersensitivity was collected by interviews. The severity of AD was evaluated by eczema area and severity index (EASI). We took blood samples to measure serum total and food-specific immunoglobulin E (IgE) levels. Based on the histories and serum IgE levels, open oral food challenge (OFC) testing was performed to confirm food hypersensitivity.

Results

Forty-two (44.2%) of the 95 AD patients had histories of food hypersensitivity. They reported that the most common suspicious foods were egg (n=13, 13.7%), pork (n=9, 9.5%) and cow milk (n=8, 8.4%). The mean EASI score was 16.05±9.76. Thirty-nine (41.1%) of the 95 patients showed elevated serum food-specific IgE levels. The specific IgE levels were elevated for egg (n=17, 17.9%), milk (n=12, 12.6%), peanut (n=10, 10.5%) and wheat (n=8, 8.4%). Fifty-one (53.8%) of 95 patients underwent open OFC, and only 7 (13.7%) of these patients showed positive reactions.

Conclusion

The overall prevalence of food hypersensitivity in patients with childhood AD in Korea was 8.3% (7/84). The most common foods causing food hypersensitivity were egg and milk. Among the foods causing hypersensitivity, AD patients in Korea often underestimated peanut, while they overestimated pork.

Establishing an allergic eczema model employing recombinant house dust mite allergens Der p 1 and Der p 2 in BALB/c mice

The major house dust mite allergens Der p 1 and Der p 2 are prevalent inducers of eczema. Der p 1 is a cysteine protease disrupting epithelial barriers, whereas Der p 2 functionally mimics the LPS-binding compound MD-2 within the TLR4 complex. In this work, we tested the percutaneous sensitizing capacity of recombinant (r) Der p 1 and Der p 2 in BALB/c mice. Mice were sensitized by percutaneous application of low (10 μg/application) and high dose (100 μg) rDer p 1 or rDer p 2, or with rDer p 1 followed by rDer p 2. Allergen-specific and total IgE antibodies were determined by ELISA. Eczema of BALB/c was classified by the itching score and corresponded to erosions. Infiltrating immune cells were identified by haematoxylin/eosin and Giemsa staining for eosinophils or mast cells, CD3 staining for T lymphocytes. Percutaneous treatments with rDer p 1, but not rDer p 2-induced specific IgG1. However, cotreatment with rDer p 1 led to increase in anti-Der p 2 IgG titres. Both allergens elicited skin erosions because of scratching, thickening of the epidermis, and eosinophil and T-cell infiltration. Our data indicate that recombinant mite allergens in the absence of adjuvant are sufficient for inducing eczema in BALB/c mice. As the enzymatic activity of an allergen might be an important cofactor for specific sensitization via the skin, Der p 1 may act as adjuvant for other allergens too. The presented mouse model is suitable for investigating the mechanisms of allergic eczema.

Risk factors and characteristics of respiratory and allergic phenotypes in early childhood

BACKGROUND

Unsupervised approaches can be used to analyze complex respiratory and allergic disorders.

OBJECTIVE

We investigated the respiratory and allergic phenotypes of children followed in the Pollution and Asthma Risk: An Infant Study (PARIS) birth cohort.

METHODS

Information on respiratory and allergic disorders, medical visits, and medications was collected during medical examinations of children at 18 months of age; biomarker data were also collected (total and allergen-specific IgE levels and eosinophilia). Phenotypes were determined by using latent class analysis. Associated risk factors were determined based on answers to questionnaires about environmental exposures.

RESULTS

Apart from a reference group, which had a low prevalence of respiratory symptoms or allergies (n=1271 [69.4%]), 3 phenotypes were identified. On the basis of clinical signs of severity and use of health care resources, we identified a mild phenotype (n=306 [16.7%]) characterized by occasional mild wheeze and 2 severe phenotypes separated by atopic status. The atopic severe phenotype (n=59 [3.2%]) included 49 (83%) children with wheezing and was characterized by a high prevalence of atopy (61% with allergenic sensitization) and atopic dermatitis (78%). In contrast, atopy was rare among children with the nonatopic severe phenotype (n=195 [11%]); this group included 88% of the children with recurrent wheezing. Risk factors for respiratory disease included parental history of asthma, male sex, siblings, day care attendance, exposure to tobacco smoke or molds, indoor renovations, and being overweight, although these factors did not have similar affects on risk for all phenotypes.

CONCLUSION

Atopy should be taken into account when assessing the risk of severe exacerbations (that require hospital-based care) in wheezing infants; precautions should be taken against respiratory irritants and molds and to prevent children from becoming overweight.

Eczema among adults: prevalence, risk factors and relation to airway diseases. Results from a large-scale population survey in Sweden

BACKGROUND

In contrast to asthma and rhinitis, few studies among adults investigating the prevalence and risk factors of eczema have been published.

OBJECTIVES

To investigate the prevalence and risk factors of eczema among adults in West Sweden. A further aim was to study the associations between asthma, rhinitis and eczema.

METHODS

A questionnaire on respiratory health was mailed in 2008 to 30,000 randomly selected subjects in West Sweden aged 16-75 years; 62% responded. The questionnaire included questions about eczema, respiratory symptoms and diseases and their possible determinants. A subgroup of 669 subjects underwent skin prick testing against common airborne allergens.

RESULTS

'Eczema ever' was reported by 40·7% and 'current eczema' by 11·5%. Both conditions were significantly more common among women. The prevalence decreased with increasing age. The coexistence of both asthma and rhinitis with eczema was common. The main risk factors were family history of allergy and asthma. The dominant environmental risk factor was occupational exposure to gas, dust or fumes. Smoking increased the risk. Eczema was associated with urbanization, while growing up on a farm was associated with a decreased risk. Added one by one to the multivariate model, asthma, allergic rhinitis and any positive skin prick test were associated with eczema.

CONCLUSIONS

Eczema among adults is a common disease with more women than men having and having had eczema. Eczema is associated with other atopic diseases and with airway symptoms. Hereditary factors and exposure to gas, dust and fumes are associated with eczema.