Appearance of atopic disease in relation to serum IgE antibodies in children followed up from birth for 4 to 15 years

Early inhalant allergen sensitization at component level: an analysis in atopic Dutch children

Background

Allergic rhinitis is a common respiratory disease in children and sensitization to inhalant allergens plays a significant role in its development. However, limited knowledge exists regarding sensitization profiles of inhalant allergen components in atopic children, particularly in the very young individuals. Understanding these profiles could provide insights into the early development of allergic rhinitis. The objective of this cross-sectional retrospective study was to evaluate the IgE-sensitization profiles to multiple inhalant allergen components and their clinical relevance in Dutch atopic children, with specific focus on children under the age of 4 years.

Methods

A total of 243 atopic children were included in the study and sensitization profiles were analyzed using multiplex microarray analysis (ISAC). Clinical information was obtained from records of a pediatric allergy outpatient clinic between 2011 and 2020. Specific IgE responses to inhalation allergen components from five allergen sources (grass pollen, tree pollen, house dust mite, cat and dog), were examined. The study encompassed children of different age groups and compared those with and without symptoms.

Results

The results demonstrated that sensitization to inhalant allergen components was present in 92% of the cohort. Sensitization was already evident at a young age (87%), including infancy, with a rapid increase in prevalence after 1 year of age. House dust mite emerged as the most predominant sensitizing allergen in early childhood, followed by tree pollen in later years. Sensitization patterns were similar between symptomatic and asymptomatic children, although symptomatic children exhibited higher frequencies and values. The sensitization profiles in very young children were comparable to those of children across all age groups.

Conclusion

These findings highlight the presence of sensitization to inhalant allergen components and the early onset of allergic rhinitis before the age of 4, including infancy, in Dutch atopic children. Notable allergen molecules in Dutch atopic children under the age of 4 years include Bet v 1, Fel d 1, Der f 1, Der p 1, Der p 10 and Phl p 4, with house dust mite sensitization being the most common among Dutch infants. Moreover, the prevalence of sensitization to inhalant allergens in this Dutch cohort surpassed that of general European populations, emphasizing the importance of early assessment and management of allergic rhinitis in young atopic children.

Windows of opportunity for tolerance induction for allergy by studying the evolution of allergic sensitization in birth cohorts

Allergic sensitization is a risk factor for developing IgE-mediated allergic diseases, which are a major cause of chronic illness world-wide. The introduction of allergen molecules to the field of allergy diagnostics has allowed dissecting the IgE response on a molecular level to pinpoint the specific disease-causing allergens. Studying birth cohorts is an essential tool for understanding the development and life course of allergy, enabling the possibility to design preventive strategies. Here we review the evolution of sensitization using data from some of the large European birth cohort studies. Differences and similarities between sensitization to food and various sources of inhalant allergens are discussed and allergen molecules of importance in early childhood predicting disease in adolescence are highlighted. Finally, we discuss windows of opportunity where intervention could be considered and address possible preventive strategies.

Role of primary and secondary prevention in atopic dermatitis

Atopic dermatitis (AD) is a serious epidemiological problem in industrialized countries. The incidence of AD has increased considerably over the last 30 years. Atopic dermatitis is a chronic, recurrent, inflammatory skin disease accompanied by strong itching. It is characterized by typical features depending on age. The parents of children suffering from AD must be prepared to change their lifestyle. They should avoid factors which can promote skin lesions and apply appropriate, regular skin care. The article describes primary prevention of AD as well as prophylactic measures to avoid skin eczema. It presents the role of infections, vaccinations, breastfeeding and the influence of domestic animals, house renovation and moulds on development of AD. The article also describes the significance of the epidermal barrier, skin colonization by microbial agents, pruritus, stress, food and inhalant allergy among people who suffer from AD.

Longitudinal observation of children with enhanced total serum IgE

BACKGROUND

Long-term studies on the evolution of elevated total IgE (tIgE) concentration are in demand.

OBJECTIVE

To investigate the prevalence of allergic diseases and influential factors in children with high tIgE levels during a 5-year period.

METHODS

Children with high tIgE levels (>100 IU/mL) were study subjects. After the 5-year follow-up, an interview with the parents, clinical examination, and evaluation of tIgE and specific IgE (sIgE) to selected food and inhalant allergens were performed.

RESULTS

The mean tIgE decreased significantly after 5 years in girls and boys regardless of the place of residence. Monosymptomatic patients accounted for most cases throughout the study, with the highest tIgE level at the beginning. After follow-up, the percentage of polysymptomatic patients increased. Their mean tIgE level was significantly higher than in the other groups. After follow-up, 11.7% of participants remained asymptomatic, and another 11.7% reported relief from symptoms. Allergy symptoms persisted in most children with normal tIgE levels. The 2-allergen sensitization was the most common through the study. Only patients sensitized to 4 allergens had unchanged levels of mean tIgE after follow-up and those with the highest mean tIgE level had a newly diagnosed sensitization to at least 1 allergen. A significant decrease of sIgE level was observed for food allergens. The values of sIgE to inhalant allergens even increased after the 5-year follow-up, despite decreased tIgE levels.

CONCLUSION

In children with allergy and an elevated concentration of tIgE, the increasing or stable value of tIgE could be a useful parameter for the prediction of the development of polysymptomatic allergy.

Reduced ex vivo stimulated IL-6 response in infants randomized to fish oil from 9 to 18 months, especially among PPARG2 and COX2 wild types

We investigated whether n-3 LCPUFA affected immune function in late infancy and explored effect-modification by single nucleotide polymorphisms (SNPs) and links to intestinal microbiota. Infants (n=105) were randomized to fish oil (FO, 1.2g/d n-3 LCPUFA) or sunflower oil (SO)-supplements from age 9-18 months. Immune function was assessed by ex vivo cytokine production in stimulated blood and plasma immunoglobulin E (IgE). We genotyped functional SNPs in PPARG2 and COX2 and analyzed fecal microbiota by 16S-rRNA terminal restriction fragment length polymorphism. FO compared to SO reduced Lactobacillus paracasei-stimulated IL-6 at 18 months (P=0.03, n=104). This effect was most pronounced among infants wild-type for PPARG2-Pro12Ala and/or COX2-T8473C (P<0.05). Predominant bacterial fragments were associated with 18 months IgE in all infants (P=0.004) (bp100) and with IL-6 production among infants weaned before 9 months (P=0.047) (bp102). Thus, FO reduced IL-6 in a genotype-modified manner. The microbiota was partly linked to IL-6 and IgE, not directly to FO.

Sensitization to food and inhalant allergens in relation to age and wheeze among children with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is common in children; however, persistence of AD with or without asthma is less common. Longitudinal studies remain limited in their ability to characterize how IgE antibody responses evolve in AD, and their relationship with asthma.

OBJECTIVE

To use a cross-sectional study design of children with active AD to analyse age-related differences in IgE antibodies and relation to wheeze.

METHODS

IgE antibodies to food and inhalant allergens were measured in children with active AD (5 months to 15 years of age, n = 66), with and without history of wheeze.

RESULTS

Whereas IgE antibodies to foods persisted at a similar prevalence and titre throughout childhood, IgE antibodies to all aeroallergens rose sharply into adolescence. From birth, the chance of sensitization for any aeroallergen increased for each 12-month increment in age (OR ≥ 1.21, P < 0.01), with the largest effect observed for dust mite (OR = 1.56, P < 0.001). A steeper age-related rise in IgE antibody titre to dust mite, but no other allergen was associated with more severe disease. Despite this, sensitization to cat was more strongly associated with wheeze (OR = 4.5, P < 0.01), and linked to Fel d 1 and Fel d 4, but not Fel d 2. Comparison of cat allergic children with AD to those without, revealed higher IgE levels to Fel d 2 and Fel d 4 (P < 0.05), but not Fel d 1.

CONCLUSIONS AND CLINICAL RELEVANCE

Differences in sensitization to cat and dust mite among young children with AD may aid in identifying those at increased risk for disease progression and development of asthma. Early sensitization to cat and risk for wheeze among children with AD may be linked to an increased risk for sensitization to a broader spectrum of allergen components from early life. Collectively, our findings argue for early intervention strategies designed to mitigate skin inflammation in children with AD.

Position document: IgE-mediated allergy to egg protein

Egg is the food that most often causes allergy in young Spanish children, with an incidence of 2.4-2.6% in the first 2 years of life. The prevalence of sensitisation and allergy to egg is greater in children with allergy to cow's milk and in those suffering atopic dermatitis. The protein component from egg white is the cause of the allergic response in child. The major allergens in egg white are ovomucoid and ovalbumin. Most of the allergic reactions affect the skin, followed by gastrointestinal and respiratory systems. Egg allergy is one of the most common causes of severe anaphylaxis. The diagnosis of egg allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which represents the gold standard for confirming the diagnosis. The treatment of egg allergy is based on the avoidance of egg protein intake. A subgroup of egg-allergic patients are tolerant to cooked egg. In these cases, only uncooked egg must necessarily be avoided. Maintaining a diet with strict egg avoidance is difficult, and transgressions are relatively common. The patient, family, and school environment should receive education and training in the avoidance of egg and in the management of possible allergic reactions. With an avoidance diet, up to 15-20% of children will remain allergic and the severity of the reactions will increase over the years. In these more severe cases of egg-allergy, it becomes more difficult to adhere to the avoidance diet over the years, with a significant decrease in patient quality of life. Oral tolerance induction can be regarded as a therapeutic option for IgE-mediated egg allergy. The anti-IgE, omalizumab, might become another genuine therapeutic option for food allergy, not only to prevent allergic reactions after a contact with egg, but also as a complementary treatment to oral tolerance induction for egg allergy, with the purpose of reducing adverse reactions. The administration of influenza vaccine to children with egg allergy is safe in children that do not manifest severe reactions after egg intake, and in children who tolerate cooked egg. The triple viral vaccine (MMR) can be given to egg-allergic children in their usual vaccination centre, with no added risk. Different medicinal products can be formulated with egg proteins, and therefore should be avoided in children with egg allergy.

Childhood food allergies: current diagnosis, treatment, and management strategies

Food allergy is a growing public health concern in the United States that affects an estimated 8% of children. Food allergy is defined as an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a specific food. Nearly 40% of children with food allergy have a history of severe reactions that if not treated immediately with proper medication can lead to hospitalization or even death. The National Institute of Allergy and Infectious Diseases (NIAID) convened an expert panel in 2010 to develop guidelines outlining evidence-based practices in diagnosing and managing food allergy. The purpose of this review is to aid clinicians in translating the NIAID guidelines into primary care practice and includes the following content domains: (1) the definition and mechanism of childhood food allergy, (2) differences between food allergy and food intolerance, (3) the epidemiology of childhood food allergy in the United States, (4) best practices derived from the NIAID guidelines focused on primary care clinicians' management of childhood food allergy, (5) emerging food allergy treatments, and (6) future directions in food allergy research and practice. Articles focused on childhood food allergy were considered for inclusion in this review. Studies were restricted to the English language and to those published within the past 40 years. A cross-listed combination of the following words, phrases, and MeSH terms was searched in PubMed and Google Scholar to identify relevant articles: food allergy, food hypersensitivity, child, pediatric, prevalence, and epidemiology. Additional sources were identified through the bibliographies of the retrieved articles.

Assessment of Total/Specific IgE Levels Against 7 Inhalant Allergens in Children Aged 3 to 6 Years in Seoul, Korea

PURPOSE

Childhood allergies are a serious problem, as they may lead to lifetime chronic disease. Determination of total and specific IgE levels is known to be a diagnostic tool for allergic sensitization; however, IgE levels are affected by various factors, such as age, sex, ethnicity, and geographic area. Thus, we evaluated the distribution of total and specific serum IgE levels against seven inhalant allergens in preschool children and examined their association with allergic diseases in Seoul, Korea.

METHODS

Total/specific serum IgE determination and skin prick tests for seven common allergens were performed on 509 children aged 3 to 6 years from 16 child care centers in Seoul, Korea. Demographic characteristics were surveyed from parents using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. A diagnosis of atopic dermatitis was made by physicians.

RESULTS

The geometric mean of total IgE was 80.48±3.80 kU/L in preschool children. IgE levels were higher in boys (boys, 102.34±3.52 kU/L; girls, 62.37±3.93 kU/L; P<0.001) and atopic subjects (atopic, 158.00±3.35 kU/L; non-atopic, 52.75±3.44 kU/L; P<0.001). An increased prevalence of atopy was associated with a high monthly household income (P=0.004) and higher maternal education level (above university-level education; P=0.009), as well as increased total IgE levels (P=0.036). Physician-diagnosed atopic dermatitis was associated with sensitization to inhalant allergens.

CONCLUSIONS

Total IgE levels were very high as compared with those in previous reports from other countries. The most common sensitized allergen was Dermatophagoides farinae, and the positive response rate peaked at age 3 years and was maintained thereafter, particularly in boys. Specific IgE levels for seven inhalant allergens varied with age in preschool children. Although further investigations are needed with a broad range of ages and various allergens, the distribution of the total and specific serum IgE levels in preschool children might help to serve as a reference value to diagnose atopy.

Colonoscopic allergen provocation test with rBet v 1 in patients with pollen-associated food allergy

BACKGROUND

After consumption of fruits, nuts, and vegetables, several patients with pollen allergy experience gastrointestinal (GI) tract symptoms that are possibly caused by pollen-associated food allergy. The aim of this study was to evaluate the colonoscopic allergen provocation (COLAP) test using the recombinant birch pollen allergen Bet v 1 (rBet v 1) for in vivo diagnosis of pollen-associated food allergy manifesting in the GI tract.

METHODS

Thirty-four patients with a history of adverse reactions to food, GI tract symptoms, and birch pollen pollinosis and five healthy controls underwent COLAP test. Twenty minutes after endoscopic challenge of the cecal mucosa with rBet v 1, the mucosal wheal and flare reaction was registered semiquantitatively, and tissue biopsy specimens were examined for eosinophil mucosal activation.

RESULTS

The mucosal reaction to rBet v 1 was correlated with the presence of pollinosis (P = 0.004), history of adverse reaction to Bet v 1-associated food allergens (P = 0.001), and tissue eosinophils' activation (P < 0.001). A wheal and flare reaction in the COLAP test was observed in 13 of 16 patients (81%) with a history of GI tract symptoms associated with the ingestion of Bet v 1-related foods and in four of 18 (22%) patients with a negative history (P < 0.001). The control group did not develop visible mucosal reactions to rBet v 1. Systemic anaphylactic reactions did not occur.

CONCLUSIONS

The mucosal administration of rBet v 1 by COLAP test provides a new diagnostic tool that might support the diagnosis of Bet v 1-associated food allergy manifesting in the GI tract.

Phadiatop Infant(®) detects IgE-mediated diseases among pre-school children: a prospective study

BACKGROUND

IgE-sensitization to food and inhalant allergens may precede and accompany the appearance of clinical symptoms of allergic diseases. The aim was to study the diagnostic capacity of Phadiatop(®) Infant (Phinf) for detecting IgE-sensitization at 5 yr of age and further to evaluate the predictive capacity of Phinf longitudinally with regard to sensitization and allergic symptoms in pre-school children.

METHODS

Two hundred and one children with complete data on sIgE testing for 10 individual allergens, Phinf analyses, and clinical evaluations at 2 and 5 yr of age were evaluated.

RESULTS

The diagnostic performance of Phinf, applied at the age of 5 and compared to specific IgE testing, gave a sensitivity of 84% and a specificity of 98%. The positive and negative predictive values were 97% and 92%, respectively. A positive Phinf test at 2 yr increased the odds 35.6-fold (95% CI 11.8-107) for IgE-sensitization and 14.7-fold (95% CI 4.4-49.7) for any allergic symptom at 5 yr of age. The association (OR) between Phinf and current symptoms was, at 2 and 5 yr of age, 3.6 (95% CI 1.6-7.9) and 18.4 (95% CI 7.4-45.8), respectively.

CONCLUSIONS

Phinf seems to be a reliable tool for predicting future sensitization as well as allergic symptoms in young children.

Pathophysiology of food allergy

In this article we review the pathophysiology of food allergy, which affects 4% of US children and 2% of adults, and is increasing in prevalence. Most food allergens share certain specific physicochemical characteristics that allow them to resist digestion, thus enhancing allergenicity. During allergic sensitization, these allergens are encountered by specialized dendritic cell populations in the gut, which leads to T-cell priming and the production of allergen-specific IgE production by B cells. Tissue-resident mast cells then bind IgE, and allergic reactions are elicited when mast cells are reexposed to allergen. Adjacent IgE molecules bound to the surface of the mast cell become cross-linked, causing mast cell degranulation and release of powerful vasoactive compounds that cause allergic symptoms.

Mechanisms of immune tolerance relevant to food allergy

The intestine has an unenviable task: to identify and respond to a constant barrage of environmental stimuli that can be both dangerous and beneficial. The proper execution of this task is central to the homeostasis of the host, and as a result, the gastrointestinal tract contains more lymphocytes than any other tissue compartment in the body, as well as unique antigen-presenting cells with specialized functions. When antigen is initially encountered through the gut, this system generates a robust T cell-mediated hyporesponsiveness called oral tolerance. Although seminal observations of oral tolerance were made a century ago, the relevant mechanisms are only beginning to be unraveled with the use of modern investigational techniques. Food allergy is among the clinical disorders that occur from a failure of this system, and therapies that seek to re-establish tolerance are currently under investigation.

Sensitization patterns to food and inhalant allergens in childhood: a comparison of non-sensitized, monosensitized, and polysensitized children

The clinical interpretation of children sensitized to numerous allergens is challenging. We examined differences between children sensitized to zero, one, or more allergens. This was a retrospective analysis of all specific IgE tests in children 0-18 yrs of age sent to our laboratory by general practitioners and hospital-based specialists for allergy testing between 1990 and 2003. Of all 9044 children tested, 5439 (60.1%) were not sensitized to any of the aeroallergens or food allergens tested. Three thousand six hundred and five children (39.9%) had one or more positive specific IgE tests, 1120 of which (31.1%) were monosensitized (73% to aeroallergens and 27% to food allergens), 1709 (47.4%) were sensitized to two to four allergens, and 776 (21.5%) to five or more allergens (polysensitization). Polysensitization was more common in children 4-11 yrs of age (24.8%) than in younger (18.7%) or older children (18.3%, p < 0.001), and more common in boys (9.8%) than in girls (7.3%, p < 0.001). Median total IgE values increased with increasing number of positive specific IgE tests (p < 0.001). House dust mite more commonly showed monosensitization (22.2%) than other aeroallergens (grass pollen 10.5%, tree pollen 3.6%, cat 2.9%, and dog 1.5%); cow's milk (27.6%) more commonly than other food allergens (hen's egg 9.7%, peanut 4.6%, wheat 0.8%, soy 0.7%). Between 55.7% (cow's milk) and 87.9% (soy) of children sensitized to food were cosensitized to aeroallergens, while only 25.4% (house dust mite) to 39.5% (dog) of children sensitized to aeroallergens were cosensitized to food. Polysensitization is common in children, in particular in boys. It is most common in school-aged children. The strong association with total serum IgE values and the striking cosensitization between biologically unrelated allergens suggest that polysensitization is the expression of a distinct clinical, more severe, atopic phenotype, and not of biologic cross-reactivity to similar allergens.

Component resolved testing for allergic sensitization

Component resolved diagnostics introduces new possibilities regarding diagnosis of allergic diseases and individualized, allergen-specific treatment. Furthermore, refinement of IgE-based testing may help elucidate the correlation or lack of correlation between allergenic sensitization and allergic disease. Novel tools to predict severe outcomes and to plan for allergen-specific treatment are necessary, and because only a small amount of blood is needed to test for a multitude of allergens and allergenic components, component resolved diagnostics is promising. A drawback is the risk of overdiagnosis and misinterpretation of the complex results of such tests. Also, the practical use and selection of allergenic components need to be evaluated in large studies including well-characterized patients and healthy, sensitized controls and with representation of different geographical regions.

Asthma prediction in school children; the value of combined IgE-antibodies and obstructive airways disease severity score

BACKGROUND

Allergic sensitisation increases the risk for asthma development. In this prospective birth cohort (Environment and Childhood Asthma) study, we hypothesized that combining quantitative measures of IgE antibodies (Sigma-IgE) and Severity score of obstructive airways disease (OAD) at 2 years of age (Severity score) is superior to predict current asthma (CA) at 10 years than either measure alone. Secondarily, we assessed if gender modified the prediction of CA.

METHODS

A follow-up study at 10 years of age was performed in 371 2-year-old children with recurrent (n = 219) or no (n = 152) bronchial obstruction with available serum analysed for Sigma-IgE to common food and inhalant allergens through a panel test, Phadiatop Infant) (Phadia, Uppsala, Sweden). Clinical variables included allergic sensitisation and exercise testing to characterise children with CA vs not CA at 10 years and the Severity score (0-12, 0 indicating no OAD) was used to assess risk modification.

RESULTS

Severity score alone explained 24% (Nagelkerke R(2) = 0.24) of the variation in CA, whereas Sigma-IgE explained only 6% (R(2) = 0.06). Combining the two increased the explanatory capacity to R(2) = 0.30. Gender interacted significantly with Sigma-IgE; whereas Severity score predicted CA in both genders, the predictive capacity of Sigma-IgE for CA at 10 years was significant in boys only.

CONCLUSION

Combining Sigma-IgE to inhalant allergens and Severity score at 2 years was superior to predict asthma at 10 years than either alone. Severity score predicted CA in both genders, whereas Sigma-IgE significantly predicted CA in boys only.

Evaluation of infants and children with refractory lower respiratory tract symptoms

OBJECTIVE

To define the diagnostic possibilities for young children who present with recurrent wheeze.

DATA SOURCES

Review of medical literature and 30 years of practice experience.

STUDY SELECTION

Relevant medical literature.

RESULTS

When evaluating an infant or child presenting with recurrent respiratory symptoms, several diagnoses must be considered. The workup should include assessment of the risk factors for asthma and careful investigation into the specific symptoms. Recurrent or persistent wheezing and/or coughing often result in a diagnosis of asthma with therapeutic trials of asthma treatment. When the therapy is ineffective, other diagnoses should be considered, including gastroesophageal reflux, protracted bacterial bronchitis, tracheobronchomalacia, and cystic fibrosis. Appropriate testing should be performed in these pediatric patients.

CONCLUSION

In young children with recurrent lower airway symptoms who have a negative modified Asthma Predictive Index result, the described diagnostic possibilities should be considered.

Cat sensitization identified by recombinant Fel d 1 several years before symptoms--results from the BAMSE cohort

Exposure to cat is one of the most important causes of allergic disease. The objective of this study was to investigate IgE reactivity to the recombinant major cat allergen, rFel d 1, as an early marker of cat sensitization. Based on questionnaires, 144 children with allergic symptoms due to cat, or where such symptoms were suspected, were selected from the birth cohort BAMSE and allocated into three study groups. Blood samples taken at age 4 and 8 yrs were analysed for IgE to rFel d 1 and cat dander extract (CDE) by quantitative ELISA (cut-off limit 0.037 kU(A)/l) and the ImmunoCAP System (cut-off limit 0.35 kU(A)/l), respectively. At 4 yrs, 25/33 children with certain allergic symptoms to cat had IgE to both rFel d 1 and CDE, while 14/42 of those suspecting symptoms at 4 had IgE to rFel d 1 and 9/42 to CDE. In a group developing symptoms after 4 yrs, 60/69 had IgE to rFel d 1 and 57/69 to CDE at 8, while 33/69 had IgE to rFel d 1 already at 4 and 26/69 to CDE. This was the only one of the three study groups where a significant increase in the IgE levels to rFel d 1 was found from 4 to 8 yrs (p < 0.001), even when only children with IgE to rFel d 1 already at 4 were included (p < 0.001). We show that the single major cat allergen rFel d 1 is at least as good as CDE in the diagnosis of cat allergy in childhood. With a sensitive rFel d 1 assay cat sensitization can be detected several years before symptoms to cat are reported.

The association between early sensitization patterns and subsequent allergic disease. The DARC birth cohort study

Prevention of allergic diseases depends on early identification of clinical markers preceding such disorders. This study describes the natural course of sensitization as measured by skin prick test (SPT) and specific immunoglobulin E (S-IgE) and analyses the association between early sensitization patterns and subsequent allergic disease at 6 yr of age. In an ongoing population-based birth cohort study of 562 children, follow-up visits were performed at 0, 3, 6, 9, 12, 18, 36, and 72 months. Visits included an interview, physical examination, SPTs, and S-IgE measurements for 12 food and inhalant allergens. The frequency of S-IgE sensitization to > or = 1 inhalant allergen was constant from 0 to 6 months (9-10%), decreased at 12-18 months before increasing from 36 months onwards. S-IgE sensitization to at least one food allergen remained constant from 0 to 6 yr. SPT sensitization to food and inhalant allergens appeared from 3 and 12 months, respectively. Early food sensitization (S-IgE) between 3 and 18 months was found to be significantly (p < 0.05) associated with atopic dermatitis (OR: 4.0 [1.6-9.9]) and asthma (OR 4.0 [1.1-12.5]) at the age of 6 yr. Children with atopic dermatitis, asthma, or rhinoconjunctivitis, and sensitization at 6 yr, were sensitized to food allergens to a large extent (53%, 42%, and 47%, respectively) already at 6 months. Early inhalant sensitization (S-IgE) did not increase the risk of later allergic disease. Early atopic dermatitis (0-18 months) was also highly associated with subsequent allergic disease. Children with early food sensitization and/or atopic dermatitis would be a proper target group for future interventional studies.

Anti-cockroach and anti-mouse IgE are associated with early wheeze and atopy in an inner-city birth cohort

BACKGROUND

The relationships between cockroach and mouse allergen exposure, anti-cockroach and anti-mouse IgE, and wheeze, rhinitis, and atopic dermatitis in children as young as age 3 years are of public health importance but have not been thoroughly evaluated.

OBJECTIVE

We hypothesized that inner-city children might have anti-cockroach and anti-mouse IgE by age 3 years, and their presence would be associated with respiratory and atopic symptoms.

METHODS

Children were followed prospectively from birth through age 3 years (n = 404). Residential levels of cockroach and mouse allergens, sera levels of anti-cockroach and anti-mouse IgE, and parental report of wheeze, rhinitis, and atopic dermatitis were measured.

RESULTS

The odds of early wheeze were significantly higher among children who had IgE to cockroach (odds ratio [OR], 3.3; 95% CI, 1.8-6.2), mouse (OR, 4.6; 95% CI, 2.3-9.0), or both (OR, 9.7; 95% CI, 3.4-27.3). The odds of rhinitis or atopic dermatitis were also higher among children with IgE to cockroach, mouse, or both. Higher IgE class to cockroach and mouse was associated with wheeze and atopic dermatitis (tests for trend, P < .002).

CONCLUSIONS

Children age 2 to 3 years who have anti-cockroach and anti-mouse IgE are at increased risk of wheeze and atopy. Moreover, a dose-response relationship was found between higher IgE class and increased prevalence of wheeze, rhinitis, or atopic dermatitis. These findings indicate the importance of reducing exposure to cockroach and mouse allergens for susceptible children.

Early skin sensitization to aeroallergens

BACKGROUND

Early detection of aeroallergen sensitization is important as a prognosis factor but may be more difficult in young children.

OBJECTIVE

We sought to demonstrate that skin sensitization to aeroallergens was present in a selected group of 0-2-year-old children and that it was associated with environmental exposure and a family history of allergic disease.

METHODS

Data on exposure and history were extracted from the files of 824 children seen in the asthma clinic and who were skin tested to a panel of aero- and food allergens.

RESULTS

Forty percent of our children demonstrated atopy, 28% were sensitized to aeroallergens, the majority of which to house dust mite. Higher sensitization rates were found in children with large weals to histamine (P<0.001) and in those who slept with soft toys [odds ratio (OR) 1.45, 95% confidence interval (CI) 1.02-2.08]. With a definition of sensitization including the size of the weal to histamine, there was a negative association with a personal history of eczema only (OR 0.66, 95% CI 0.45-0.99). There was no gender-dependent effect and no association with day-care attendance.

CONCLUSION

This is one of the largest studies to evaluate skin testing in a selected population of young children. We found a high prevalence of sensitization to aeroallergens, which was associated with exposure to soft toys. Further follow-up of this population will allow assessment of the predictive value of this sensitization.

Sensitization to turnip rape and oilseed rape in children with atopic dermatitis: a case-control study

Turnip rape and oilseed rape 2S albumins are new allergens in children with atopic dermatitis suspected for food allergy. We recently found that 11% (206/1887) of these children had a positive skin prick test to seeds of oilseed rape (Brassica napus) and/or turnip rape (Brassica rapa). In the present case-control study we examined how the children with atopic dermatitis sensitized to turnip rape and oilseed rape had been breast-fed and whether they had some common sensitization pattern to certain foods or pollens. A total of 64 children with atopic dermatitis and a positive skin prick test to turnip rape and/or oilseed rape (>or=5 mm) were examined. Sixty-four age- and sex-matched children with atopic dermatitis but negative skin prick tests to turnip rape and oilseed rape served as case controls. The turnip rape and/or oilseed rape sensitized children with atopic dermatitis had significantly more often positive skin prick tests reactions and IgE antibodies to various foods (cow's milk, egg, wheat, mustard; p < 0.01) and pollens (birch, timothy, mugwort; p < 0.01) than the control children. They had been exclusively breast-fed for a longer period (median 4 months; p < 0.05) and had more often associated asthma (36%) and allergic rhinitis (44%). Children with atopic dermatitis sensitized to oilseed rape and turnip rape had high frequency of associated sensitizations to all foods and pollens tested showing that oilseed plant sensitization affects especially atopic children who have been sensitized to multiple allergens.

Sensitization to inhalant allergens between 4 and 8 years of age is a dynamic process: results from the BAMSE birth cohort

BACKGROUND

There is limited knowledge of the development of IgE-antibody levels over time in childhood, with respect to persistency and co-sensitization to specific inhalant allergens.

METHODS

Data from 2033 children participating in the BAMSE birth cohort was used. Background factors and clinical parameters were obtained and IgE antibody (ab) levels to eight common airborne allergens were measured (>or=0.35 kU(A)/L) when the children were 4 and 8 years of age.

RESULTS

Between 4 and 8 years the proportion of children sensitized to any of the inhalant allergens tested increased from 15% to 25%. At 4 years IgE-ab to birch and cat dominated, whereas at the age of 8, there was a considerable increase in the proportion of sensitization to timothy and dog. Except for mites and moulds, IgE-ab levels to all aeroallergens increased significantly between 4 and 8 years among those already sensitized at 4. Transient sensitization to inhalant allergen was uncommon. Furthermore, sensitization to birch pollen at 4 years increased the risk for becoming sensitized to timothy, cat and dog later in life. Such an association was not observed among those sensitized primarily to animal dander.

CONCLUSIONS

There is a prominent process of sensitization at pre-school age to inhalant allergens, and in Northern Europe sensitization to birch pollen early in life seems to be important for this process. Such a process has a probable impact on the development of allergic disease in the growing child.

Use of Phadiatop Infant in diagnosis of specific sensitization in young children with wheeze or eczema

Wheezing and eczema are common symptoms in young children and it is important to disclose sensitization for correct management. The objective of this study was to assess the diagnostic values of Phadiatop Infant, an in vitro test for graded determination of immunoglobulin E (IgE) antibodies to food and inhalant allergens. One-hundred and forty-nine children (median age 1.4 yr) with symptoms of wheezing (51%) eczema (28%) or a combination of both (21%) were classified as atopic or non-atopic based on case history, atopic history, physical examination and determination of IgE antibodies. The clinical performance of Phadiatop Infant was evaluated for 145 children against this classification in a blinded manner to the allergist. Fifty-one children were classified as atopic of which Phadiatop Infant identified 49. Ninety-four were non-atopic of which the test identified 90. This resulted in a sensitivity of 96%, a specificity of 96%, a positive and a negative predictive value of 94% and 98%, respectively. Logistic regression showed that probability had to be assessed as atopic increased with increasing Phadiatop Infant values. These results suggest that Phadiatop Infant can be recommended as an adjunct to the clinical information in the differential diagnosis on IgE-mediated allergy in young children. The test thus provides an opportunity for early correct diagnosis and identification of subjects at risk for whom intervention may be necessary.

Early predictors for developing allergic disease and asthma: examining separate steps in the 'allergic march'

BACKGROUND

Sensitization and symptoms of allergic disease are strongly correlated, but little is known about the early clinical precursors of the development of allergen sensitization in childhood. The aim of this study was to identify these predictors, and to examine separately the effect of early sensitization on subsequent wheeze, asthma, rhinitis and eczema.

METHODS

In the Childhood Asthma Prevention Study, children with a family history of asthma were assessed for allergen sensitization, total serum IgE, wheeze, asthma, eczema and rhinitis at ages 18 months and 5 years. To examine predictors, at 18 months, for subsequent sensitization, children who were non-sensitized at 18 months and had data on sensitization at 5 years were investigated, n=375. To examine the predictors, at age 18 months, of subsequent onset of symptoms, children who did not have wheeze, asthma, eczema or rhinitis at 18 months were followed-up at 5 years, n=177.

RESULTS

Among children who were non-sensitized at age 18 months, the presence of eczema [adjusted relative risk (aRR), 1.67, 95% confidence interval (CI) 1.20-2.33], but not wheeze, asthma or rhinitis, was an independent predictor of the onset of sensitization by age 5 years. Among children who were asymptomatic at age 18 months, sensitization to any allergen at 18 months was an independent predictor for the presence of wheeze (aRR 2.41, 95% CI 1.28-4.55), asthma (aRR 4.66, 95% CI 1.88-11.54) and rhinitis (aRR 1.77, 95% CI 1.08-2.90), but not for the development of eczema (aRR 0.78, 95% CI 0.23-2.64) at 5 years.

CONCLUSION

In non-sensitized children, eczema, but not wheeze, asthma or rhinitis is a predictor for subsequent development of sensitization. This suggests that early childhood eczema, rather than wheeze and rhinitis, may promote subsequent allergen sensitization and raises the possibility that early management of eczema may reduce the prevalence of sensitization in children.

The natural history of peanut and tree nut allergy

Peanut and tree nut allergies were once thought to be permanent. Recent studies have shown that about 20% and 10%, respectively, of young patients may outgrow peanut and tree nut allergies. For the majority of patients, however, the natural history is not favorable. In addition, approximately 8% of patients who outgrow peanut allergy may suffer a recurrence. The rising prevalence of these allergies, coupled with the knowledge that allergic reactions to these foods have the potential to be severe or fatal and that accidental exposures are common, makes developing effective treatments to alter the natural history of peanut and tree nut allergies even more crucial for those who will not outgrow them. At this time, avoidance of the offending foods and being prepared to treat a potential reaction after accidental ingestion is the only treatment, but many promising therapeutic interventions are being investigated.

Effect of cosensitization with buckwheat flour extract on the production of house dust mite-specific IgE

There are studies reporting food sensitization in infancy increases the risk of sensitization to inhalants later in life. We performed a study to evaluate whether cosensitization with buckwheat (BW) has an effect on the production of house dust mite-IgE. C3H/HeJ mice (4 weeks, female) were sensitized with house dust mite (HDM)/Al (OH)(3), intraperitoneally on day 0, followed by 4 intranasal sensitizations (on days 14, 15, 16, and 21). Group 1 was cosensitized intragastrically with BW/cholera toxin (CT) (on days 0, 1, 2, 7, and 18) during sensitization with HDM, group 2 was cosensitized intragastrically with CT only (on days 0, 1, 2, 7, and 18), and group 3 was used as controls. HDM- and BW-IgE and antigen-specific T-cell proliferation and cytokine production were evaluated. In Group 1, BW-IgE levels were highest at week 4, and the HDM-IgE at week 3 (98.45+/-64.37 ng/mL and 169.86+/-55.54 ng/mL, respectively). In Group 2, HDM-IgE levels reached a peak at week 3, remarkably higher (810.52+/-233.29 ng/mL) compared to those of Group 1 (169.86+/-55.54 ng/mL). The interleukin (IL)-4 and interferon (IFN)-beta in the HDM-stimulated culture supernatants of splenocytes were not significantly different among groups. We postulate that the cosensitization with BW may down-regulate the specific IgE response to HDM.

Probiotics in prevention of IgE-associated eczema: a double-blind, randomized, placebo-controlled trial

BACKGROUND

An altered microbial exposure may underlie the increase of allergic diseases in affluent societies. Probiotics may alleviate and even prevent eczema in infants.

OBJECTIVE

To prevent eczema and sensitization in infants with a family history of allergic disease by oral supplementation with the probiotic Lactobacillus reuteri.

METHODS

Double-blind, randomized, placebo-controlled trial, which comprised 232 families with allergic disease, of whom 188 completed the study. The mothers received L reuteri ATCC 55730 (1 x 10(8) colony forming units) daily from gestational week 36 until delivery. Their babies then continued with the same product from birth until 12 months of age and were followed up for another year. Primary outcome was allergic disease, with or without positive skin prick test or circulating IgE to food allergens.

RESULTS

The cumulative incidence of eczema was similar, 36% in the treated versus 34% in the placebo group. The L reuteri group had less IgE-associated eczema during the second year, 8% versus 20% (P = .02), however. Skin prick test reactivity was also less common in the treated than in the placebo group, significantly so for infants with mothers with allergies, 14% versus 31% (P = .02). Wheeze and other potentially allergic diseases were not affected.

CONCLUSION

Although a preventive effect of probiotics on infant eczema was not confirmed, the treated infants had less IgE-associated eczema at 2 years of age and therefore possibly run a reduced risk to develop later respiratory allergic disease.

CLINICAL IMPLICATION

Probiotics may reduce the incidence of IgE-associated eczema in infancy.

T and B cell responses to HDM allergens and antigens

House dust mites provide well-characterized proteins to study human responses to inhaled antigens. Even in the absence of allergy they induce a high frequency of T cell precursors. The healthy response manifests by T cell proliferation and Th1 cytokines with little antibody. Responses of allergic people include Th1 and Th2 cytokines and IgE, IgG1, and IgG4 antibodies. Regulatory cells limit effector responses in healthy people. About half the IgE and IgG antibodies bind the group 1 and 2 allergens and 30% bind the group 4, 5, and 7 allergens. Although HLA independent, the recognition of the group 1 allergen shows an immunodominant region and a T cell receptor bias. The major allergens are not produced in higher amounts than many of the poorly non-allergenic proteins. The non-allergenic mite ferritin antigen shows high T cell proliferative responses with mixed cytokine production.

Sensitization to different pollens and allergic disease in 4-year-old Swedish children

BACKGROUND

Although the relationship between sensitization to different inhalant allergens in adolescents and adults has been intensively studied, information concerning sensitization in children is scarce in particular to pollens.

OBJECTIVES

In 4-year-old children to elucidate the pollen immunoglobulin (IgE) antibody profile (birch only, timothy only and combinations of three pollens (birch, timothy or mugwort) and to relate the results to other inhalant and food allergens, as well as the presence of allergic diseases.

METHODS

A total of 2551 4-year-old children belonging to a prospective birth cohort, which has been followed longitudinally (BAMSE), were investigated with respect to IgE antibodies to pollen and other inhalant and food allergens, and expression of allergic disease, based on questionnaire data.

RESULTS

Eleven percent (n=285) of the children were sensitized to pollen. Birch was the dominating cause of pollen sensitization (birch sensitization only, n=133); followed by timothy grass pollen (n=56) and a combination of two (n=64) or three (n=30) pollens. A remarkably high proportion of the children sensitized only to birch was also sensitized to other inhalant allergens. This was not seen for children sensitized only to timothy. The highest frequencies of IgE reactivity to food were found in the group of children sensitized to the combination of birch, timothy and mugwort pollen. Children sensitized to timothy only, exhibited symptoms of allergic disease significantly less frequently compared with children sensitized to birch only. Sensitization to birch pollen was found to be closely associated with rhinitis and eczema compared with asthma. The highest frequency of asthma and/or rhinitis and/or eczema was reported in children sensitized to at least two pollens.

CONCLUSION

Our results demonstrate that birch is the dominating source of pollen sensitization at the age of four in Sweden. This might associate with the pattern of sensitization to other inhalant and food allergens as well as influence on the expression of allergic disease in this particular age group.

Relationship between IgE and specific aeroallergen sensitivity in Alaskan native children

BACKGROUND

The relationship between atopic disease and serum IgE levels varies among populations and geographic regions. The close association of atopy with IgE may not occur in subarctic populations as it does in developed countries in temperate climates.

OBJECTIVE

To evaluate the relationship between total and specific IgE concentrations and clinical atopy in 5- to 8-year-old Alaskan native children.

METHODS

Medical record reviews, interviews, physical examinations, serum IgE measurements, and radioallergosorbent testing (RAST) were performed.

RESULTS

The IgE geometric mean was 122.1 IU/mL. Fifty-eight percent of patients had IgE levels greater than 70 IU/mL, and 17% had levels greater than 1,000 IU/mL; 14% had RAST values greater than 0.35 kU/L. Both IgE levels greater than 70 IU/mL and greater than 1,000 IU/mL were associated with RAST values greater than 0.35 IU/L (P = .004) and early wheezing (P = .005) but not with current wheezing, asthma, eczema, or a history of allergies. A RAST value greater than 3.51 kU/L was associated with eczema (P = .04) but not with allergies or wheezing. Children with current wheezing were more likely to have allergies (P = .03) but not eczema, an IgE level greater than 70 IU/mL, or a positive RAST value. Children hospitalized with respiratory syncytial virus (RSV) were not more likely than controls to have current wheezing.

CONCLUSIONS

Elevated serum IgE concentrations, including levels greater than 1,000 IU/mL, are common among Alaskan native children; positive RAST reactions to aeroallergens are not. The IgE levels do not relate to wheezing, eczema, a history of allergies, or past hospitalization for RSV infection but likely reflect infections other than RSV and environmental factors in subarctic indigenous populations.

Defining childhood atopic phenotypes to investigate the association of atopic sensitization with allergic disease

AIMS

Although atopic sensitization is common in childhood, its relationship to clinical allergic disease remains incompletely understood. We therefore sought to explore this relationship by defining sensitization based atopic phenotypes.

METHODS

Children were recruited at birth (n = 1456) and reviewed at 1, 2, 4 and 10 years. Skin prick testing (SPT) to common allergens was done at 4 (n = 980) and 10 years (n = 1036) with lung function (n = 981), bronchial challenge (n = 784) and serum IgE (n = 953) testing at 10. Atopic phenotypes were defined, by sensitization pattern, for children with SPT at both 4 and 10 years (n = 823).

RESULTS

Of phenotyped children, 68.0% were never atopic, 4.3% early childhood atopic (only atopic at age 4), 16.5% chronic childhood atopics (at 4 and 10 years) and 11.2% delayed childhood atopics (only at 10). Never atopics showed small but identifiable prevalence of allergic diseases such as asthma, eczema and rhinitis. Amongst allergen-sensitized subjects, aeroallergen predominated over food sensitization throughout childhood. Chronic childhood atopics showed highest prevalence of lifetime plus persistent wheeze, eczema and rhinitis, increased prevalence of aeroallergen sensitization, some evidence of persistent food sensitization, significantly greater cord IgE than never atopics (P = 0.006), plus higher total IgE (P < 0.001) and bronchial hyper-responsiveness (P < 0.001) at 10 years than other phenotypes.

CONCLUSION

A proportion of childhood eczema, rhinitis and asthma is nonatopic. The commonest childhood pattern of atopy is chronic sensitization, associated with early, persisting and clinically significant allergic disease. The currently accepted childhood 'Allergic March' may oversimplify the natural history of childhood atopy and allergic disease.

The atopic march: the pattern of allergic disease development in childhood

The sequential development of allergic disease manifestations during early childhood is often referred to as the atopic march. Various epidemiologic and birth-cohort studies have begun to elucidate the evolution of allergic disease manifestations and to identify populations at risk for disease. These studies, along with intervention studies, emphasize the effects of environmental factors and genetic predisposition on the atopic march. This article discusses the populations at risk for the development of atopic conditions and the interventions that have been explored in attempts to modify the progression of allergic disease.

Hope for the hygiene hypothesis: when the dirt hits the fan

The hygiene hypothesis was developed in response to data suggesting that the increase in allergic diseases as well as asthma was secondary to a reduced exposure to infectious stimuli. Indeed, the epidemiologic changes, resulting in an increase in atopic disease, have been impressive and intriguing. Furthermore, although there clearly is a genetic component to atopic diseases, genetics cannot account for a marked increase in the incidence and prevalence of allergic manifestations within a few generations. Thus, environmental factors have been suggested as responsible for the changing prevalence. There are two--not mutually exclusive--possibilities, namely, that substances that promote atopy have been added to the environment or that factors that provided protection from allergic disease were lost from the environment. Both outdoor and indoor pollution, along with a long list of other environmental factors, have been proposed. It is of interest that in many developed countries, certain types of pollution have decreased, whereas the prevalence of atopic disease has increased. In this review, we have explored a detailed analysis of a large number of studies that have focused on this issue and suggest that, although the hygiene hypothesis has merit, the stimuli responsible for the new epidemiology remain enigmatic.

Prevalence of atopic dermatitis and serum IgE values in nursery school children in Ishigaki Island, Okinawa, Japan

There have been many studies of the prevalence of atopic dermatitis (AD), but few population-based epidemiologic studies measure the prevalence in Japan among children aged 5 years and younger. We examined the prevalence of AD, serum total IgE levels and specific IgE antibodies to 10 common allergens among children in Ishigaki Island, Okinawa, Japan in 2001. We also obtained information on the predictability of the U.K. Working Party diagnostic questionnaire criteria for AD in this population. Five hundred and sixty five children aged 5 years and younger were enrolled in this study with informed consent from their parents. The questionnaire of the U.K. Working Party diagnostic criteria for AD was translated into Japanese, and the parents completed the questionnaire sheet. Physical examination and blood sampling were done for all children. Thirty-nine out of the 565 (6.9%) children were diagnosed with AD by physical examination. The total and specific IgE levels were significantly higher in the children with AD than in those without AD. High levels of total IgE were found in 33.3% of the children with AD. A specific IgE to one or more allergens was detected in 64.1% of children with AD. However, a substantial population of children without AD also had high levels of total IgE (12.7%) and a specific IgE to one or more allergens (30.2%), and the increment of total and specific IgE levels was significantly associated with age. The percentage of positive answers to the questionnaire of the U.K. Working Party diagnostic criteria for AD was significantly higher in children with AD (59.0%) than in children without AD (5.3%) (P<0.0001). Its specificity was 94.7%. The false negative rate was 41%. In conclusion, the prevalence of AD was relatively low in children in Ishigaki Island. High levels of total IgE were found in only one third of children with AD under 5 years of age. The Japanese translated form of the questionnaire of the U.K. Working Party diagnostic criteria for AD should be refined to improve its sensitivity.

Reduced immunoglobulin E and allergy among adults with glioma compared with controls

We and others have reported previously that adults with glioma are 1.5- to 4-fold less likely than controls to report a variety of allergic conditions. The consistent nature of this relationship calls for a biological explanation so that preventative or therapeutic modalities can be explored. We enrolled 403 newly diagnosed adult glioma cases in the San Francisco Bay Area over a 3-year period using a population-based cancer registry and 402 age/gender/ethnicity frequency-matched controls identified via random digit dialing. We assessed total, food-specific, and respiratory-specific IgE in available case (n = 228) and control (n = 289) serum samples. IgE levels were associated with gender, age, smoking status, and ethnicity among cases and/or controls. Among the cases, IgE levels were not associated with aspects of glioma therapy including radiation, chemotherapy, or tumor resection. Total IgE levels were lower in cases than controls: age/gender/ethnicity/education/smoking-adjusted odds ratio (OR) for elevated versus normal total IgE was 0.37 [95% confidence interval (CI), 0.22-0.64]. For the food panel, OR was 0.12 (95% CI, 0.04-0.41). For the respiratory panel, OR was 0.76 (95% CI, 0.52-1.1). Among respiratory allergies, late age of onset (>12 years) but not IgE levels defined a group with strong associations with risk (OR, 0.50; 95% CI, 0.33-0.75). These results corroborate and strengthen our findings of an inverse association between allergic reactions and glioma by showing a relationship with a biomarker for allergy and cancer for the first time. Furthermore, the results indicate a complex relationship between allergic disease and glioma risk that varies by allergen and allergic pathology.

Atopic characteristics of children with recurrent wheezing at high risk for the development of childhood asthma

BACKGROUND

Few studies have characterized the atopic profile of toddler-aged children with recurrent wheezing at high risk of the development of persistent asthma. Objective We sought to determine the atopic profile of toddler-aged children with frequent wheeze at high risk for the development of persistent asthma who either had a parental history of asthma, a personal history of atopic dermatitis, or both.

METHODS

Participants enrolled in the Prevention of Early Asthma in Kids study (n = 285) on the basis of a modified Asthma Predictive Index were characterized on the basis of allergy and asthma questionnaire responses and allergy skin puncture test results.

RESULTS

The majority of the children (60.7%, n = 148) were sensitized to either food or aeroallergens. Male children were significantly more likely to be sensitized to aeroallergens ( P = .03) and to have a blood eosinophil level of 4% or greater ( P = .03) and a total serum IgE level of greater than 100 IU/mL ( P = .0004). Additionally, eosinophilia and total serum IgE level had the strongest correlation with aeroallergen sensitization.

CONCLUSION

The high prevalence of aeroallergen sensitization in this high-risk cohort suggests that aeroallergens might have an important role in the early development of asthma. As such, the Prevention of Early Asthma in Kids cohort appears to be an appropriate cohort in which to test whether early intervention with an inhaled corticosteroid can significantly attenuate, or perhaps even prevent, the allergic march from the initial stages of allergic sensitization to the subsequent development of asthma in toddlers with episodic wheezing.

Determination of thymus and activation-regulated chemokine (TARC)-contents in scales of atopic dermatitis

BACKGROUND

Thymus and activation-regulated chemokine (TARC) is a cytokine which selectively controls the migration of type 2-helper T lymphocytes into inflammatory lesions, and the serum level is strongly associated with disease severity of atopic dermatitis (AD).

OBJECTIVE

To examine the role of TARC in the pathogenesis of AD, we determined TARC-contents in the scales obtained from lesional skin of the patients with AD.

RESULTS

High amount of TARC was detected in the scales of lesional skin obtained from the patients with AD, and the amount was well correlated with the serum IgE levels but not with the blood eosinophil counts. The TARC-content in the lesional scales was not correlated with a-431C/T polymorphism of TARC promotor gene, suggesting other regulating mechanisms in TARC production in the lesion.

CONCLUSION

High amount of TARC is produced in the kesion of AD, and analysis of cytokine content in lesional scales may provide some tools to clarify the pathogenesis of AD.