The natural course of cow's milk allergy and the development of atopic diseases into adulthood.

BACKGROUND: Previous studies have investigated the natural course of cow's milk allergy (CMA) and development of atopic diseases into adolescence. Studies with long-term follow-up into adulthood are lacking. The aim of this study was to investigate (a) the natural course of CMA in a 1-year birth cohort of Danish children from birth until 15 and 26 years of age and (b) the development of atopic diseases in a group of children with CMA (group A) compared to a random sample of 276 children from the same birth cohort (group B). METHODS: A birth cohort of 1749 newborns was investigated prospectively for the development of CMA and atopic diseases. During the first year of life and at 18 months and 3, 5, 10, 15, and 26 years of age, questionnaire-based interviews, physical examination, skin prick tests, and specific IgE testing, and from 10 years also spirometry, were carried out. RESULTS: Thirty-nine (2.2%) were diagnosed with CMA. The recovery rate was 87%, 92%, and 97% at 3, 5, and 26 years of age. Compared to group B, group A had significantly (P < .05) higher prevalence of asthma and rhinoconjunctivitis at 15 years of age, and at 26 years of age, group A had significantly higher prevalence of asthma and atopic dermatitis. The follow-up rate was 85% (A) and 70% (B). CONCLUSION: CMA has a good prognosis regarding recovery rate. However, CMA, especially IgE-mediated, in early childhood predicts a high prevalence of atopic diseases into adulthood.

Maternal phthalate exposure and asthma, rhinitis and eczema in 552 children aged 5 years; a prospective cohort study.

BACKGROUND: Prenatal phthalate exposure has been suggested to alter immune responses and increase the risk of asthma, eczema and rhinitis. However, few studies have examined the effects in prospective cohorts and only one examined rhinitis. We therefore studied associations between maternal urinary concentrations of phthalate metabolites and asthma, eczema and rhinitis in offspring aged 5 years. METHODS: From 552 pregnant women in the Odense Child Cohort, we quantified urinary concentrations of 12 phthalate metabolites in third trimester. We assessed asthma, rhinitis and eczema in their offspring at age 5 years with a questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC), and conducted logistic regression adjusting for relevant confounders. RESULTS: 7.4% of the children had asthma, 11.7% eczema and 9.2% rhinitis. Phthalate exposure was low compared to previous cohorts. No significant associations between prenatal phthalate exposure and asthma were found. Odds ratios (ORs) of child rhinitis with a doubling in ΣDiNPm and di-2-ethylhexyl phthalate metabolite (ΣDEHPm) concentrations were, respectively, 1.15 (95% confidence interval (CI) 0.97,1.36) and 1.21 (CI 0.93,1.58). The OR of eczema when doubling ΣDiNPm was 1.24 (CI 1.00,1.55), whereas the OR of using medicine against eczema when doubling a di-ethyl phthalate (DEP) metabolite was 0.81 (CI 0.68,0.96). CONCLUSION: The lack of association between maternal phthalate exposure and asthma in the offspring may be due to low exposure and difficulties in determining asthma in 5-year-olds. The higher odds of rhinitis may raise public concern but further research in larger cohorts of older children is warranted.

Probiotics in late infancy reduce the incidence of eczema: A randomized controlled trial.

BACKGROUND: Allergic diseases are common and represent a considerable health and economic burden worldwide. We aimed to examine the effect of a combination of two probiotic strains administered in late infancy and early childhood on the development of allergic diseases and sensitization. METHODS: In this double-blind, placebo-controlled intervention trial, participants were randomized to receive a daily mixture of Lactobacillus rhamnosus and Bifidobacterium animalis subsp lactis or placebo-starting prior to attending day care. The intervention period was 6 months, and the parents answered web-based questionnaires on allergic symptoms and doctor's diagnosed allergic disease monthly. IgE was measured at baseline and follow-up. RESULTS: A total of 290 participants were randomized: 144 in the probiotic group and 146 in the placebo group. Mean age at intervention start was 10.1 months. At follow-up (mean age 16.1 months), the incidence of eczema was 4.2% in the probiotic group and 11.5% in the placebo group (P = 0.036). The incidence of asthma and conjunctivitis did not differ between groups, and no children presented with rhinitis. Sensitization was equal in the two groups at intervention start (7.5% and 9.5%, respectively), and two children in each group were sensitized during the intervention. CONCLUSIONS: We observed a significantly lower incidence of eczema in the probiotic group compared to the placebo group. The probiotics were administered in late infancy-prior to attending day care-suggesting a broader window of opportunity using probiotics in the prevention of eczema. The incidence of asthma, rhinitis, conjunctivitis, and sensitization did not differ.

Association between prenatal exposure to perfluoroalkyl substances and asthma in 5-year-old children in the Odense Child Cohort.

BACKGROUND: Asthma is the most common non-communicable disease in children. Prenatal exposure to perfluoroalkyl substances (PFASs), a group of persistent environmental chemicals with endocrine disrupting abilities, has been associated with immunomodulation and may contribute to the aetiology of asthma. We investigated the associations between prenatal exposure to five PFASs and asthma in 5-year-old children. METHODS: We studied 981 mother-child pairs within the Odense Child Cohort (OCC), Denmark. We measured perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) in maternal serum donated in early pregnancy. A standardized questionnaire based on the International Study of Asthma and Allergies in Childhood (ISAAC) was used to assess wheeze, self-reported asthma and doctor-diagnosed asthma among children at age 5 years. Associations were examined using logistic regression analyses adjusting for parity, maternal educational level, maternal pre-pregnancy BMI, asthma predisposition and child sex. RESULTS: Among the 5-year-old children 18.6% reported wheeze and 7.1% reported asthma. We found no association between prenatal exposure to PFAS and doctor-diagnosed asthma or wheeze. Prenatal PFAS exposure was associated with self-reported asthma, although only significant for PFNA (OR = 1.84, 95% CI 1.03,3.23). CONCLUSION: Our findings support the suggested immunomodulatory effects of PFASs, however, additional studies are warranted. In order to verify our findings, it is important to re-examine the children with postnatal measurements of serum PFAS concentrations and additional clinical diagnostic testing at an older age where an asthma diagnosis is more valid.

Current state and future of pediatric allergology in Europe: A road map.

The history of pediatric allergology (PA) in Europe is relatively youthful, dating back to 1984, when a small group of pediatricians founded the European Working Group on Pediatric Allergy and Immunology-later giving rise to ESPACI (European Society on Pediatric Allergology and Clinical Immunology). In 1990, the first dedicated journal, Pediatric Allergy and Immunology (PAI), was founded. There are striking differences across Europe, and even within European countries, in relation to the training pathways for doctors seeing children with allergic disease(s). In 2016, the EAACIClemens von Pirquet Foundation (CvP) organized and sponsored a workshop with the European Academy of Allergy and Clinical Immunology (EAACI) Pediatric Section. This collaboration focussed on the future of PA and specifically on education, research, and networking/ advocacy. The delegates representing many countries across Europe have endorsed the concept that optimal care of children with allergic diseases is delivered by pediatricians who have received dedicated training in allergy, or allergists who have received dedicated training in pediatrics. In order to meet the needs of children and families with allergic disease(s), the pediatric allergist is highly encouraged to develop several networks. Our challenge is to reinforce a clear strategic approach to scientific excellence to across our member base and to ensure and enhance the relevance of European pediatric research in allergy. With research opportunities in basic, translational, clinical, and epidemiologic trials, more trainees and trained specialists are needed and it is an exciting time to be a pediatric allergologist.

Early-life sensitization to hen's egg predicts asthma and rhinoconjunctivitis at 14 years of age.

BACKGROUND: Sensitization to both inhalant and food allergens has been shown to be risk factors for development of asthma and rhinoconjunctivitis (RC). However, few studies have addressed the role of transient or persistent IgE sensitization to specific allergens in early life for later development of allergic diseases. The aim of this study was to explore the association between transient and persistent sensitization in early life and the development of asthma and RC at 6 and 14 years. METHODS: The Danish Allergy Research Center (DARC) cohort is a prospective non-interventional birth cohort study comprising 562 children. For the purpose of this study, we examined a subgroup of the original cohort with specific IgE measured at, at least 3 of 4 follow-ups between 3 and 18 months of age (n = 366). Multiple logistic regression models were used to investigate the association between transient and persistent early-life sensitization to groups of and to individual allergens and asthma and RC at 6 and 14 years compared to a reference group with no sensitization. RESULTS: Both transient early-life sensitization and persistent early-life sensitization to cow's milk or hen's egg proteins were associated with asthma (aOR 3.99[1.41-11.32] and 5.95[1.78-19.92]) and RC (aOR 2.94[1.19-7.28] and 6.18[1.86-20.53]) at 14 years, this association being driven mainly by sensitization to hen's egg. Transient early-life sensitization to house dust mite (HDM) had increased risk of asthma (aOR 3.80[1.17-12.41]) at 14 years. CONCLUSIONS: Early transient IgE sensitization and persistent IgE sensitization to hen's egg were associated with asthma and RC at 14 years. Furthermore, sensitization to HDM was associated with asthma at 14 years.

The prevalence of atopic diseases and the patterns of sensitization in adolescence.

BACKGROUND: Atopic diseases are among the most common chronic diseases in adolescents, and it is uncertain whether the prevalence of atopic diseases has reached a plateau or is still increasing. The use of the ISAAC (International Study of Asthma and Allergy in Childhood) questionnaire has provided comparable prevalence rates from many countries, whereas studies including clinical examinations and strict diagnostic criteria are scarce. We aimed to investigate the prevalence of atopic diseases, the pattern of sensitization, and comorbidities at 14 years in a prospective birth cohort. METHODS: The children were examined eight times from birth to 14 years. Visits included questionnaire-based interviews, clinical examination, skin prick test, and specific IgE. RESULTS: Follow-up rate at 14 years was 66.2%. The 12-month prevalence of any atopic disease was high (40.3%) mostly due to a high prevalence of rhinoconjunctivitis (32.8%), whereas the prevalence of asthma was 12.9% and of atopic dermatitis 8.1%. In children with at least one atopic disease, 60% were sensitized, while only 16% of those without atopic diseases were sensitized. The frequency of sensitization depended on the phenotype. Among children with rhinoconjunctivitis only, rhinoconjunctivitis with concomitant asthma or atopic dermatitis or both 62.5%, 81.5%, 70%, and 100%, respectively, were sensitized, whereas it was 7.7% and 33.3% of children with only asthma or atopic dermatitis. CONCLUSION: The prevalence of rhinoconjunctivitis was high in adolescence. Children with rhinoconjunctivitis with and without comorbidities were frequently sensitized. Children with asthma without concomitant allergic rhinoconjunctivitis were rarely sensitized.

Low patch test reactivity to nickel in unselected adolescents tested repeatedly with nickel in infancy.

BACKGROUND: It is questionable how repeated patch tests with nickel sulfate in infancy affect nickel patch test reactivity at a later age. METHODS: The Danish Allergy Research Center (DARC) cohort encompasses 562 infants invited to a clinical examination including patch tests with nickel sulfate six times during the first 36 months of life. At the follow-up investigation at 14 years of age (2013-2014), participants were offered re-patch tests with nickel sulfate. The Odense Adolescence Cohort Study TOACS cohort encompasses 1501 schoolchildren evaluated for the first time at 14 years of age (1995-1996) including clinical examination and nickel sulfate patch tests. The prevalence of nickel sensitization in the DARC cohort was compared to the prevalence in the TOACS cohort at 14 years of age. RESULTS: Nickel sulfate sensitization was found in 1.2% of the participants from the DARC cohort tested repeatedly with nickel sulfate in early childhood and retested at 14 years of age compared to 8.6% of the participants from the TOACS cohort patch-tested for the first time at 14 years of age using the same patch test system and test concentration. CONCLUSION: The significant difference in nickel patch test reactivity comparing the two cohorts may reflect an immunologic effect or the effect of nickel regulation.

Consensus Communication on Early Peanut Introduction and Prevention of Peanut Allergy in High-Risk Infants.

The purpose of this brief communication is to highlight emerging evidence regarding potential benefits of supporting early rather than delayed peanut introduction during the period of complementary food introduction in infants. This document should be considered as interim guidance based on consensus among the following organizations: American Academy of Allergy, Asthma, and Immunology, American Academy of Pediatrics, American College of Allergy, Asthma, and Immunology, Australasian Society of Clinical Immunology and Allergy, Canadian Society of Allergy and Clinical Immunology, European Academy of Allergy and Clinical Immunology, Israel Association of Allergy and Clinical Immunology, Japanese Society for Allergology, Society for Pediatric Dermatology, and World Allergy Organization. More formal guidelines regarding early-life, complementary feeding practices and the risk of allergy development will follow in the next year from the National Institute of Allergy and Infectious Diseases-sponsored Working Group and the European Academy of Allergy and Clinical Immunology.

Consensus communication on early peanut introduction and the prevention of peanut allergy in high-risk infants.

The purpose of this brief communication is to highlight emerging evidence to existing guidelines regarding potential benefits of supporting early, rather than delayed, peanut introduction during the period of complementary food introduction in infants. This document should be considered as interim guidance based on consensus among the following organizations: American Academy of Allergy, Asthma & Immunology, American Academy of Pediatrics, American College of Allergy, Asthma & Immunology, Australasian Society of Clinical Immunology and Allergy, Canadian Society of Allergy and Clinical Immunology, European Academy of Allergy and Clinical Immunology, Israel Association of Allergy and Clinical Immunology, Japanese Society for Allergology, Society for Pediatric Dermatology, and World Allergy Organization. More formal guidelines regarding early-life, complementary feeding practices and the risk of allergy development will follow in the next year from the National Institute of Allergy and Infectious Diseases-sponsored Working Group and the European Academy of Allergy and Clinical Immunology.

Having older siblings is associated with gut microbiota development during early childhood.

BACKGROUND: Evidence suggests that early life infections, presence of older siblings and furred pets in the household affect the risk of developing allergic diseases through altered microbial exposure. Recently, low gut microbial diversity during infancy has also been linked with later development of allergies. We investigated whether presence of older siblings, furred pets and early life infections affected gut microbial communities at 9 and 18 months of age and whether these differences were associated with the cumulative prevalence of atopic symptoms of eczema and asthmatic bronchitis at 3 years of age. Bacterial compositions and diversity indices were determined in fecal samples collected from 114 infants in the SKOT I cohort at age 9 and 18 months by 16S rRNA gene sequencing. These were compared to the presence of older siblings, furred pets and early life infections and the cumulative prevalence of diagnosed asthmatic bronchitis and self-reported eczema at 3 years of age. RESULTS: The number of older siblings correlated positively with bacterial diversity (p = 0.030), diversity of the phyla Firmicutes (p = 0.013) and Bacteroidetes (p = 0.004) and bacterial richness (p = 0.006) at 18 months. Further, having older siblings was associated with increased relative abundance of several bacterial taxa at both 9 and 18 months of age. Compared to the effect of having siblings, presence of household furred pets and early life infections had less pronounced effects on the gut microbiota. Gut microbiota characteristics were not significantly associated with cumulative occurrence of eczema and asthmatic bronchitis during the first 3 years of life. CONCLUSIONS: Presence of older siblings is associated with increased gut microbial diversity and richness during early childhood, which could contribute to the substantiation of the hygiene hypothesis. However, no associations were found between gut microbiota and atopic symptoms of eczema and asthmatic bronchitis during early childhood and thus further studies are required to elucidate whether sibling-associated gut microbial changes influence development of allergies later in childhood.

Can family history and cord blood IgE predict sensitization and allergic diseases up to adulthood?

BACKGROUND: Long-term studies of the predictive value of family history and cord blood IgE level until adulthood are few, and their conclusions have been contradictory. METHODS: Screening of total IgE in 1617 cord blood samples was performed in a Danish birth cohort. All infants with cord blood IgE (CB-IgE) ≥ 0.5 kU/l and a corresponding randomly chosen group with CB-IgE <0.5 kU/l were chosen for follow-up. Questionnaire-based interviews, physical examination, specific IgE testing, and from 10 yr also spirometry, were carried out at 1½, 5, 10, 15, and 26 yr. Predefined diagnostic criteria were used. RESULTS: A total of 455 infants were included, 188 with CB-IgE ≥ 0.5 kU/l and 267 with CB-IgE <0.5 kU/l. Follow-up rates were high, 288 (63%) attended the 26-yr follow-up. Family history and elevated CB-IgE were significantly associated to allergic disease until 26 yr. Concerning any allergic symptoms at 1½ yr the positive and negative predictive values (PPV and NPV), the sensitivity and specificity of CB-IgE ≥ 0.5 kU/l, was 29%, 81%, 54%, and 61%, respectively. The corresponding figures at 26 yr were 46%, 62%, 43%, and 65%. Overall, family history as well as CB-IgE ≥ 0.5 kU/l was associated with high NPV and specificity, but low PPV and sensitivity. CONCLUSION: Although family history and elevated CB-IgE were significantly associated with primarily atopic disease until 26 yr, none of these were strong predictors for subsequent sensitization and allergic symptoms from childhood until early adulthood. It appears that the predictive capacity of CB-IgE decreases in adolescence and early adulthood.

Consensus communication on early peanut introduction and the prevention of peanut allergy in high-risk infants.

The purpose of this brief communication is to highlight emerging evidence to existing guidelines regarding potential benefits of supporting early, rather than delayed, peanut introduction during the period of complementary food introduction in infants. This document should be considered as interim guidance based on consensus among the following organizations: American Academy of Allergy, Asthma & Immunology, American Academy of Pediatrics, American College of Allergy, Asthma & Immunology, Australasian Society of Clinical Immunology and Allergy, Canadian Society of Allergy and Clinical Immunology, European Academy of Allergy and Clinical Immunology, Israel Association of Allergy and Clinical Immunology, Japanese Society for Allergology, Society for Pediatric Dermatology, and World Allergy Organization. More formal guidelines regarding early-life, complementary feeding practices and the risk of allergy development will follow in the next year from the National Institute of Allergy and Infectious Diseases-sponsored Working Group and the European Academy of Allergy and Clinical Immunology.

Phthalate exposure through different pathways and allergic sensitization in preschool children with asthma, allergic rhinoconjunctivitis and atopic dermatitis.

Studies in rodents indicate that phthalates can function as adjuvants, increasing the potency of allergens. Meanwhile, epidemiological studies have produced inconsistent findings regarding relationships between phthalate exposures and allergic disease in humans. The present study examined phthalate exposure and allergic sensitization in a large group of 3-5 year old children: 300 random controls and 200 cases with asthma, rhinoconjunctivitis or atopic dermatitis as reported in questionnaires. The children were clinically examined to confirm their health status. Blood samples were analyzed for IgE sensitization to 20 allergens. Adjusted logistic regressions were used to look for associations between phthalate exposure indicators (mass fractions in dust from children's homes and daycares, metabolites in urine, and estimated daily indoor intakes from dust ingestion, inhalation and dermal absorption) and sensitization and allergic disease. No direct associations were found between phthalate exposures and asthma, rhinoconjunctivitis or atopic dermatitis. However, among children with these diseases, there were significant associations between non-dietary exposures to DnBP, BBzP and DEHP in the indoor environment (mass fractions in dust or daily indoor intakes from dust ingestion, inhalation and dermal absorption) and allergic sensitization. Some exposure pathways were more strongly associated with sensitization than others, although the results are not conclusive and require confirmation. A number of the associations depended on accounting for a child's exposure in more than one environment (i.e., daycare facility as well as home). Significant associations were not observed between phthalate metabolites in urine, which reflected exposure from diet as well as indoor pathways, and allergic sensitization.

A workshop report on the development of the Cow's Milk-related Symptom Score awareness tool for young children.

UNLABELLED: Clinicians with expertise in managing children with gastrointestinal problems and/or atopic diseases attended a workshop in Brussels in September 2014 to review the literature and determine whether a clinical score derived from symptoms associated with the ingestion of cow's milk proteins could help primary healthcare providers. The Cow's Milk-related Symptom Score (CoMiSS), which considers general manifestations, dermatological, gastrointestinal and respiratory symptoms, was developed as an awareness tool for cow's milk-related symptoms. It can also be used to evaluate and quantify the evolution of symptoms during therapeutic interventions, but does not diagnose cow's milk protein allergy and does not replace a food challenge. Its usefulness needs to be evaluated by a prospective randomised study. CONCLUSION: The CoMiSS provides primary healthcare clinicians with a simple, fast and easy-to-use awareness tool for cow's milk-related symptoms.

Allergy and asthma prevention 2014.

Asthma and allergic diseases have become one of the epidemics of the 21st century in developed countries. Much of the success of other areas of medicine, such as infectious diseases, lies on preventive measures. Thus, much effort is also being placed lately in the prevention of asthma and allergy. This manuscript reviews the current evidence, divided into four areas of activity. Interventions modifying environmental exposure to allergens have provided inconsistent results, with multifaceted interventions being more effective in the prevention of asthma. Regarding nutrition, the use of hydrolyzed formulas in high-risk infants reduces the incidence of atopic dermatitis, while there is for now not enough evidence to recommend other dietary modifications, prebiotics, probiotics, or other microbial products. Pharmacologic agents used until now for prevention have not proved useful, while there is hope that antiviral vaccines could be useful in the future. Allergen-specific immunotherapy is effective for the treatment of allergic patients with symptoms; the study of its value for primary and secondary prevention of asthma and allergy is in its very preliminary phases. The lack of success in the prevention of these disorders lies on their complexity, which involves many genetic, epigenetic, and environmental interactions. There is a need to identify target populations, involved mechanisms and interactions, and the best interventions. These must be effective, feasible, implementable, and affordable.

The natural course of sensitization and allergic diseases from childhood to adulthood.

BACKGROUND: Longitudinal prospective population-based birth cohort studies of the natural history of sensitization and allergic diseases from childhood to adulthood are few. The aim of the present prospective study was to investigate the natural course of sensitization and allergic diseases in a random population-based sample of 276 children from a 1-year birth cohort of unselected Danish children followed from birth to 26 years of age. METHODS: Questionnaire-based interviews, physical examination, skin prick tests, specific IgE testing, and from 10 years also spirometry, were carried out at 1.5, 5, 10, 15 and 26 years of age. Predefined diagnostic criteria were used. RESULTS: Follow-up rates were high, 193 (70%) attended the 26-year follow-up. The prevalence of current eczema was stable during childhood; 13% (1.5 yrs.), 9.2% (5 yrs.), 10.8% (10 yrs.), and 9.8% (15 yrs.), and 5.7% at 26 yrs. From birth to 26 years the cumulative prevalence of eczema, food allergy, asthma, and rhinoconjunctivitis was 23.5%, 13.8%, 17%, and 27.9% respectively. More than half of the participants had one or more allergic disease in the period between birth and 26 years of age. The rates of sensitization (S-IgE = 0.35 kU/l) were 8%, 23%, 26%, 32%, and 31% at 1.5, 5, 10, 15, and 26 years of age, respectively. Sensitization to food allergens was most prevalent in early infancy, whereas sensitization to inhalant allergens dominated later on. CONCLUSION: The results support the concept of the allergic march. Allergic diseases are not only occurring in childhood but persist into adulthood.

The history of pediatric allergy in Europe - from a working group to ESPACI and SP-EAACI.

A Working Group on Pediatric Allergology was formed in 1984, which rapidly developed to become the European Society on Pediatric Allergology and Clinical Immunology (ESPACI) in 1988 with its own journal, Pediatric Allergology and Immunology. ESPACI worked together with the European Academy of Allergology and Clinical Immunology (EAACI) to form a Section of Pediatrics within EAACI (SP-EAACI) in 1996. The ESPACI and the SP-EAACI formally merged in 2001. Within the EAACI organization, the Pediatric Section has continued to grow. The Pediatric Section is working to develop pediatric allergology across Europe, focusing on postgraduate education, facilitating the research agenda and advocating for children and adolescents with allergies.

Positive nickel patch tests in infants are of low clinical relevance and rarely reproducible.

BACKGROUND: We have previously reported patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3-18 months of age. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity provided a patch test with an empty Finn chamber was negative. A reproducible positive reaction was seen in 8.6% of the infants. The objective of this study is to follow-up on infants with alleged nickel sensitivity. METHODS: A total of 562 infants were included in the cohort and patch tested with nickel sulphate (ICDRG guidelines). The 26 children with a positive patch test reaction to nickel sulphate at 12 and 18 months were offered repeated patch tests at 3 and 6 yr. RESULTS: Among the 21 children tested at both 12 months, 18 months and at 3 and 6 yr only 2 of 21 had reproducible nickel reactions (one clinically relevant), 13 of 21 were negative and 6 of 21 were negative at 3 or 6 yr. CONCLUSIONS: Only 9.5% of the children had reproducible nickel sulphate reactivity, while 62% became negative. The results are noteworthy and can be interpreted in different ways: Repeated nickel patch tests did not cause patch test sensitization. The test reactions in infancy are probably of irritant or non-specific nature. Hence, nickel patch tests should only be performed in small children if there is a clinical suspicion of nickel-induced allergic contact dermatitis.

Prevalence of IgE sensitization in Danish children with suspected asthma.

OBJECTIVE: The aim of this article was to estimate the prevalence of IgE sensitization in Danish children with suspected asthma and to characterize the pattern of sensitization. STUDY DESIGN: We performed a cross-sectional study including 1744 children from 0 to 15 yr suspected of asthma who were referred to pediatric outpatient clinics in the region of southern Denmark from 2003 to 2005. The children were subjected to an extensive questionnaire-based interview, clinical examination, and both skin prick testing (SPT) and IgE measurements for 17 allergens. RESULTS: Asthma was confirmed in 1024 of the 1744 children. Among the children in whom the asthma diagnosis was confirmed, sensitization to one or more of the 17 allergens tested was found in 67.5% by either SPT or s-IgE ≥ class 2. Sensitization to any food allergen was found in 31.1%, to any outdoor allergen in 36.2%, and to any indoor allergen in 51.8%. Sensitization to cockroach and latex was rare. We found a weak correlation between SPT and s-IgE among food allergens and a more distinct correlation among inhalant allergens. Surprisingly, 30.1% of children in whom the asthma diagnosis was disproven used inhaled corticosteroids (ICS). On the contrary, 32.5% of the children for whom the asthma diagnosis was verified were not treated with ICS. CONCLUSION: We have found a high prevalence of sensitization among children with verified asthma. Our study supports relevant allergy testing in all children with verified asthma and emphasizes the importance of a thorough asthma diagnosis before prescribing continuous inhaled corticosteroids to children.