The Journal of Allergy and Clinical Immunology: In Practice, Feb 1, 2022
BACKGROUND Allergic sensitization increases the risk of and asthma and allergic rhinitis, but the... more BACKGROUND Allergic sensitization increases the risk of and asthma and allergic rhinitis, but the impact of age at onset of sensitization is less studied. OBJECTIVE To examine the cumulative incidence of asthma and rhinitis up to age 19 years in relation to age at onset of sensitization to airborne allergens. METHOD All children in grade one and two (median age 8 years) in two municipalities in Northern Sweden were invited to skin prick tests and a questionnaire about allergic diseases, and 88% participated. At ages 12 and 19 years the protocol was repeated, and n=1510 individuals participated in all three examinations. Specific IgE was collected in a random sample at age 19, n=770. Onset of sensitization was defined; ≤8 years, 8-12 years, 12-19 years, and never sensitized. Adjusted Poisson regression was utilized to calculate risk ratios. RESULTS At age 19, those sensitized ≤8 year had the highest risk of asthma (RR 4.68 (95%CI 3.14-6.97)) and rhinitis (RR 22.3 (95%CI 13.3-37.6)), and 84% had developed either asthma or rhinitis. The combination of sensitization ≤8 year and family history of allergic diseases rendered high risks for asthma (RR 10.6 (6.71-16.7)) and rhinitis (RR 36.3 (18.9-69.7). Individuals sensitized ≤8 year showed significantly highest level of sensitization, as judged by number of positive skin tests and titers of specific IgE. CONCLUSION The majority of individuals with sensitization ≤8 years developed asthma or rhinitis before young adulthood. The high level of sensitization in early sensitized contribute to the high incidence of allergic airway conditions.
Background: While Health Related Quality of Life has been investigated among children with IgE-me... more Background: While Health Related Quality of Life has been investigated among children with IgE-mediated food allergy, less is known about quality of life among children with other types of hypersensitivity to food. The aim of this study was to investigate Health Related Quality of Life (HRQL) in children with and without food hypersensitivity. Further, we compared HRQL between children with different phenotypes of food hypersensitivity. Methods: In a large population-based cohort of schoolchildren in Northern Sweden, the parents of 2612 (96% of invited) completed a questionnaire. All 125 (5%) children who reported complete elimination of milk, egg, fish or wheat due to food hypersensitivity were invited to a clinical examination and 94 children participated. Of these, 75 children also completed a generic (KIDSCREEN-52) and a disease-specific HRQL questionnaire (FAQLQ-TF). Thereafter, these children were categorised into the different phenotypes: current food allergy, outgrown food allergy, and lactose intolerance. Additionally, 209 children with unrestricted diets answered the generic questionnaire. Results: The median score of all KIDSCREEN-52 domains were above the population norm of 50 both in children with and without food hypersensitivity. No significant differences in distribution in generic or disease-specific HRQL were found between children with or without food hypersensitivity. There were no significant differences in HRQL between children with different phenotypes of food hypersensitivity. However, children with current food allergy tended to have the lowest HRQL. Further, poor HRQL defined as ≥75th percentile for the disease specific score was significantly more common in the current food allergy phenotype in the domain Emotional impact and the total FAQLQ, compared to the other phenotypes. Conclusions: In this population-based study, 12-13 year old children reported good HRQL regardless of having food hypersensitivity or not. However, the children with the current phenotype reported lower HRQL than the other phenotypes.
Background: Double-blind, placebo-controlled food challenges are the gold standard for diagnosing... more Background: Double-blind, placebo-controlled food challenges are the gold standard for diagnosing the clinical relevance of a suspected food allergy. Hitherto there are no descriptions on how adol ...
Background: Few population-based cohort studies have examined reported food hypersensitivity long... more Background: Few population-based cohort studies have examined reported food hypersensitivity longitudinally. We investigated prevalence, incidence and remission of perceived food hypersensitivity among schoolchildren from 8 to 12 years of age, and risk factors associated with incidence and remission. Methods: A population-based cohort including all 7-8 year-old children in three Swedish towns was recruited in 2006. A total of 2,585 (96% of invited) children participated in a parental questionnaire. The children in two of the towns, n = 1,700 (90% of invited) also participated in skin-prick-testing with airborne allergens. The cohort was followed using the same methods at 11-12 years of age. At study follow up, specific IgE to foods was analyzed in a randomized subset of children (n = 652). Results: The prevalence of perceived food hypersensitivity increased from 21% at 8 years to 26% at 12 years of age. During this four-year-period, the cumulative incidence of food hypersensitivity was high (15%), as was remission (33%). This pattern was particularly evident for hypersensitivity to cow´s milk, while the incidence of hypersensitivity to other foods was lower. Female sex, allergic heredity, current rhinitis and allergic sensitization were associated with the incidence of food hypersensitivity and allergic sensitization was negatively associated with remission. Risk-factor-patterns for both incidence and remission were different for hypersensitivity to milk compared with hypersensitivity to other foods. Generally, the agreement between reported food hypersensitivity and IgE-sensitization to the implicated food was poor. Conclusions: In this longitudinal, population-based cohort-study perceived food hypersensitivity was common among children between ages 8 and 12, often transient and not well correlated with food-specific IgE. While these findings suggest an overestimated prevalence of food hypersensitivity, the public-health-significance remains high as they reflect the perceived reality to which the children adapt their life and food intakes.
Sensitization to animal allergen components in relation to asthma among young adults in Northern ... more Sensitization to animal allergen components in relation to asthma among young adults in Northern Sweden
Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE)... more Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE) are among a number of immune-mediated reactions to food that are thought to occur primarily via non-IgE-mediated pathways. All three are typically present in infancy and are triggered most commonly by cow's milk protein. The usual presenting features are vomiting with lethargy and dehydration in FPIES; bloody and mucous stools in FPIA P; and diarrhea with malabsorption and failure to thrive in FPE. Diagnosis is based on convincing history and resolution of symptoms with food avoidance; confirmatory diagnostic testing other than food challenge is lacking. The mainstay of management is avoidance of the suspected inciting food, with interval challenge to assess for resolution, which usually occurs in the first years of life. Studies published in the past few years clarify common presenting features, report additional culprit foods, address potential biomarkers, and suggest new management strategies. Keywords Food protein-induced enterocolitis. Food protein-induced allergic proctocolitis. Allergic enterocolitis. Allergic proctocolitis. Allergic colitis. Food protein-induced enteropathy. Food allergy. FPIAP. FPE. FPIES This article is part of the Topical Collection on Food Allergy
Animal sensitization is a major determinant of asthma in children. Component-resolved studies of ... more Animal sensitization is a major determinant of asthma in children. Component-resolved studies of unselected pediatric populations are lacking. The aim was to describe sensitization to animal components and the association with asthma and rhinitis in animal-sensitized schoolchildren. A random sample of 696 children (11-12 years) from a Swedish population-based cohort was tested for sensitization to cat, dog, and horse dander using ImmunoCAP. Sera from animal-sensitized children were further analyzed by microarray including three allergen components from cat, four from dog, and two from horse. The parents completed an expanded ISAAC questionnaire. Of 259 animal-sensitized children (≥0.1 kUA /l), 51% were sensitized to all three, 23% to two, and 25% to one species. Current asthma and asthma symptoms following contact with cats were associated with co-sensitization to Fel d 1 and Fel d 4. This association was seen already at moderate-level sensitization (1-15 ISU) to Fel d 4, at which level most children were sensitized to Fel d 1, as well. In dog-sensitized children, the majority was sensitized to more than one dog component, and co-sensitization to Can f 5 and Can f 1/f 2 conferred the greatest risk for asthma. Sensitization to the highly cross-reactive serum albumins was uncommon and not associated with asthma. Among schoolchildren in northern Sweden, where mite allergy is uncommon, furry animals were the primary perennial sensitizers. Asthma was associated with higher levels of component sensitization, and sensitization to more than one component from the same animal conferred the greatest risk.
Background: Few population-based cohort studies have examined reported food hypersensitivity long... more Background: Few population-based cohort studies have examined reported food hypersensitivity longitudinally. We investigated prevalence, incidence and remission of perceived food hypersensitivity among schoolchildren from 8 to 12 years of age, and risk factors associated with incidence and remission. Methods: A population-based cohort including all 7-8 year-old children in three Swedish towns was recruited in 2006. A total of 2,585 (96% of invited) children participated in a parental questionnaire. The children in two of the towns, n = 1,700 (90% of invited) also participated in skin-prick-testing with airborne allergens. The cohort was followed using the same methods at 11-12 years of age. At study follow up, specific IgE to foods was analyzed in a randomized subset of children (n = 652). Results: The prevalence of perceived food hypersensitivity increased from 21% at 8 years to 26% at 12 years of age. During this four-year-period, the cumulative incidence of food hypersensitivity was high (15%), as was remission (33%). This pattern was particularly evident for hypersensitivity to cow´s milk, while the incidence of hypersensitivity to other foods was lower. Female sex, allergic heredity, current rhinitis and allergic sensitization were associated with the incidence of food hypersensitivity and allergic sensitization was negatively associated with remission. Risk-factor-patterns for both incidence and remission were different for hypersensitivity to milk compared with hypersensitivity to other foods. Generally, the agreement between reported food hypersensitivity and IgE-sensitization to the implicated food was poor. Conclusions: In this longitudinal, population-based cohort-study perceived food hypersensitivity was common among children between ages 8 and 12, often transient and not well correlated with food-specific IgE. While these findings suggest an overestimated prevalence of food hypersensitivity, the public-health-significance remains high as they reflect the perceived reality to which the children adapt their life and food intakes.
Furry animal sensitisation to allergen components and asthma diagnosis in a child cohort from nor... more Furry animal sensitisation to allergen components and asthma diagnosis in a child cohort from northern Sweden
The Journal of Allergy and Clinical Immunology, Feb 1, 2015
RATIONALE: Atopic sensitization increases the risk of asthma. Our aim was to investigate patterns... more RATIONALE: Atopic sensitization increases the risk of asthma. Our aim was to investigate patterns of sensitization to allergens and allergen components in relation to asthma among adults in a Swedish populationbased sample. METHODS: A questionnaire targeting asthma was sent to 30 000 randomly selected adults (16-75 y) in west Sweden. Of the 18 087 responders, a randomly selected sample of 2000 subjects and in addition all 1536 subjects reporting asthma were invited to clinical examinations. Sera were received from 906 subjects with asthma and from 1000 without reported asthma (controls) and were tested for three IgE panels of inhalant and food allergens. Samples with a level of IgE >0.35 kU A /l were further analyzed for IgE against each individual allergen and nine allergen components related to furry animals. RESULTS: The risk of being sensitized to any of the 21 tested allergens was significantly higher in the asthma group. The risk was highest for individuals sensitized to furry animals (risk ratios 4,5-7,9). The level of IgE to animal allergens was also significantly higher in the asthma group. Cosensitization to more than one cat and/or dog allergen component conferred a greater risk for asthma. Simultaneous sensitization to the cat allergens Fel d 1 and Fel d 4 was associated with asthma. CONCLUSIONS: In this large population-based study subjects with asthma were commonly co-sensitized to more than one animal allergen component, especially to Fel d 1 and Fel d 4. Component-resolved analysis has the potential to increase precision when assessing asthma in adults.
To cite this article: Winberg A, Nordström L, Strinnholm Å, Nylander A, Jons€ all A, Rönmark E, W... more To cite this article: Winberg A, Nordström L, Strinnholm Å, Nylander A, Jons€ all A, Rönmark E, West CE. New validated recipes for double-blind placebo-controlled lowdose food challenges.
Background: There is need for prognostic markers for symptomatic food allergy since current diagn... more Background: There is need for prognostic markers for symptomatic food allergy since current diagnostic methods are insufficient and/or time and labor consuming. Objective: To estimate the cytokine mRNA profiles in peripheral blood mononuclear cells (PBMC) before and after a double-blind placebo-controlled food challenge series in schoolchildren with suspected allergy to milk, egg or cod and in healthy controls. Analyses of fecal inflammatory biomarkers before and after the challenge were included. Methods: Twelve-year-old children from a population-based cohort reporting complete avoidance of milk, egg, cod or wheat due to perceived hypersensitivity were clinically examined and those with suspected food allergy were evaluated with a 3-session double-blind placebo-controlled food challenge (n = 18). Seven healthy controls participated in a double-blind challenge with egg. Before and after the challenge series, the cytokine mRNA expression was quantified for 13 cytokines discriminating between humoral Th2-, cytotoxic Th1-, regulatory Th3/Tr1-and inflammatory responses. Fecal calprotectin and eosinophil-derived neurotoxin (EDN) were also analyzed in children with suspected food allergy before and after the challenge series. Results: Pre challenge, children with suspected food allergy had higher IL-13 and TNF-a expression and lower IFN-c and IL-15 expression compared to healthy controls (all p < 0.05). Children with challengeproven food allergy had increased IL13 and IL-10 expression compared to the levels seen in negative challenges (p < 0.05). Post challenge, IL-1b and IL-6 mRNA levels were elevated in the food allergic children compared to controls (p < 0.05). Fecal calprotectin and EDN levels were higher in challenge-proven food allergy compared to a negative challenge although not statistically significantly. Conclusion & clinical relevance: Increased baseline mRNA levels of the Th2-related cytokine IL-13 and the regulatory cytokine IL-10 predicted a positive food challenge outcome. These cytokines in combination with fecal calprotectin and EDN might serve as future prognostic markers for symptomatic, IgEmediated food allergy but need further validation in a larger patient cohort.
Article type : Regular Article 10-year review found increasing incidence trends of emergency egg ... more Article type : Regular Article 10-year review found increasing incidence trends of emergency egg allergy reactions and food induced anaphylaxis in children
Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is i... more Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is incomplete. The purpose of this study was to investigate the prevalence of allergies to milk, egg, cod, and wheat using reported data, clinical examinations, and double-blind placebocontrolled food challenges, and to describe the phenotypes of reported food hypersensitivity in a cohort of Swedish schoolchildren. Methods In a population-based cohort of 12-year-old children, the parents of 2612 (96% of invited) completed a questionnaire. Specific IgE antibodies to foods were analyzed in a random sample (n=695). Children reporting complete avoidance of milk, egg, cod, or wheat due to perceived hypersensitivity and without physician-diagnosed celiac disease were invited to undergo clinical examination that included specific IgE testing, a celiac screening test, and categorization into phenotypes of food hypersensitivity according to preset criteria. Children with possible food allergy were further evaluated with double-blind challenges. Results In this cohort, the prevalence of reported food allergy to milk, egg, cod, or wheat was 4.8%. Food allergy was diagnosed in 1.4% of the children after clinical evaluation and in 0.6% following double-blind placebo-controlled food challenge. After clinical examination, children who completely avoided one or more essential foods due to perceived food hypersensitivity were categorized with the following phenotypes: allergy (29%), outgrown allergy (19%), lactose intolerance (40%), and unclear (12%). Conclusions There was a high discrepancy in the prevalence of allergy to milk, egg, cod and wheat as assessed by reported data, clinical evaluation, and double-blind food challenges. Food
Background During several decades the prevalence of atopic dermatitis (AD) has increased and now ... more Background During several decades the prevalence of atopic dermatitis (AD) has increased and now affects about one fifth of all children in high-income countries. While the increase continues in lower income countries, the AD prevalence might have reached a plateau in high-income countries. Objectives The aim of this study was to investigate trends in prevalence of AD and atopic comorbidity among schoolchildren in Sweden. Methods The study population consisted of three cohorts of children in Norrbotten, Sweden, from 1996 (n=3430), 2006 (n=2585), and 2017 (n=2785), median age 8 years. A questionnaire was used, including questions from the ISAAC protocol, identical in all three cohorts. Trends in prevalence of AD was estimated, as well as trends in atopic comorbidity. Prevalence was estimated both according to the ISAAC definition of AD, and by adding reported diagnosis by a physician (D-AD). Results The prevalence of AD decreased in the last decade, from 22.8 % (1996) and 21,3 % (200...
The Journal of Allergy and Clinical Immunology: In Practice, Feb 1, 2022
BACKGROUND Allergic sensitization increases the risk of and asthma and allergic rhinitis, but the... more BACKGROUND Allergic sensitization increases the risk of and asthma and allergic rhinitis, but the impact of age at onset of sensitization is less studied. OBJECTIVE To examine the cumulative incidence of asthma and rhinitis up to age 19 years in relation to age at onset of sensitization to airborne allergens. METHOD All children in grade one and two (median age 8 years) in two municipalities in Northern Sweden were invited to skin prick tests and a questionnaire about allergic diseases, and 88% participated. At ages 12 and 19 years the protocol was repeated, and n=1510 individuals participated in all three examinations. Specific IgE was collected in a random sample at age 19, n=770. Onset of sensitization was defined; ≤8 years, 8-12 years, 12-19 years, and never sensitized. Adjusted Poisson regression was utilized to calculate risk ratios. RESULTS At age 19, those sensitized ≤8 year had the highest risk of asthma (RR 4.68 (95%CI 3.14-6.97)) and rhinitis (RR 22.3 (95%CI 13.3-37.6)), and 84% had developed either asthma or rhinitis. The combination of sensitization ≤8 year and family history of allergic diseases rendered high risks for asthma (RR 10.6 (6.71-16.7)) and rhinitis (RR 36.3 (18.9-69.7). Individuals sensitized ≤8 year showed significantly highest level of sensitization, as judged by number of positive skin tests and titers of specific IgE. CONCLUSION The majority of individuals with sensitization ≤8 years developed asthma or rhinitis before young adulthood. The high level of sensitization in early sensitized contribute to the high incidence of allergic airway conditions.
Background: While Health Related Quality of Life has been investigated among children with IgE-me... more Background: While Health Related Quality of Life has been investigated among children with IgE-mediated food allergy, less is known about quality of life among children with other types of hypersensitivity to food. The aim of this study was to investigate Health Related Quality of Life (HRQL) in children with and without food hypersensitivity. Further, we compared HRQL between children with different phenotypes of food hypersensitivity. Methods: In a large population-based cohort of schoolchildren in Northern Sweden, the parents of 2612 (96% of invited) completed a questionnaire. All 125 (5%) children who reported complete elimination of milk, egg, fish or wheat due to food hypersensitivity were invited to a clinical examination and 94 children participated. Of these, 75 children also completed a generic (KIDSCREEN-52) and a disease-specific HRQL questionnaire (FAQLQ-TF). Thereafter, these children were categorised into the different phenotypes: current food allergy, outgrown food allergy, and lactose intolerance. Additionally, 209 children with unrestricted diets answered the generic questionnaire. Results: The median score of all KIDSCREEN-52 domains were above the population norm of 50 both in children with and without food hypersensitivity. No significant differences in distribution in generic or disease-specific HRQL were found between children with or without food hypersensitivity. There were no significant differences in HRQL between children with different phenotypes of food hypersensitivity. However, children with current food allergy tended to have the lowest HRQL. Further, poor HRQL defined as ≥75th percentile for the disease specific score was significantly more common in the current food allergy phenotype in the domain Emotional impact and the total FAQLQ, compared to the other phenotypes. Conclusions: In this population-based study, 12-13 year old children reported good HRQL regardless of having food hypersensitivity or not. However, the children with the current phenotype reported lower HRQL than the other phenotypes.
Background: Double-blind, placebo-controlled food challenges are the gold standard for diagnosing... more Background: Double-blind, placebo-controlled food challenges are the gold standard for diagnosing the clinical relevance of a suspected food allergy. Hitherto there are no descriptions on how adol ...
Background: Few population-based cohort studies have examined reported food hypersensitivity long... more Background: Few population-based cohort studies have examined reported food hypersensitivity longitudinally. We investigated prevalence, incidence and remission of perceived food hypersensitivity among schoolchildren from 8 to 12 years of age, and risk factors associated with incidence and remission. Methods: A population-based cohort including all 7-8 year-old children in three Swedish towns was recruited in 2006. A total of 2,585 (96% of invited) children participated in a parental questionnaire. The children in two of the towns, n = 1,700 (90% of invited) also participated in skin-prick-testing with airborne allergens. The cohort was followed using the same methods at 11-12 years of age. At study follow up, specific IgE to foods was analyzed in a randomized subset of children (n = 652). Results: The prevalence of perceived food hypersensitivity increased from 21% at 8 years to 26% at 12 years of age. During this four-year-period, the cumulative incidence of food hypersensitivity was high (15%), as was remission (33%). This pattern was particularly evident for hypersensitivity to cow´s milk, while the incidence of hypersensitivity to other foods was lower. Female sex, allergic heredity, current rhinitis and allergic sensitization were associated with the incidence of food hypersensitivity and allergic sensitization was negatively associated with remission. Risk-factor-patterns for both incidence and remission were different for hypersensitivity to milk compared with hypersensitivity to other foods. Generally, the agreement between reported food hypersensitivity and IgE-sensitization to the implicated food was poor. Conclusions: In this longitudinal, population-based cohort-study perceived food hypersensitivity was common among children between ages 8 and 12, often transient and not well correlated with food-specific IgE. While these findings suggest an overestimated prevalence of food hypersensitivity, the public-health-significance remains high as they reflect the perceived reality to which the children adapt their life and food intakes.
Sensitization to animal allergen components in relation to asthma among young adults in Northern ... more Sensitization to animal allergen components in relation to asthma among young adults in Northern Sweden
Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE)... more Food protein-induced enterocolitis (FPIES), allergic proctocolitis (FPIAP), and enteropathy (FPE) are among a number of immune-mediated reactions to food that are thought to occur primarily via non-IgE-mediated pathways. All three are typically present in infancy and are triggered most commonly by cow's milk protein. The usual presenting features are vomiting with lethargy and dehydration in FPIES; bloody and mucous stools in FPIA P; and diarrhea with malabsorption and failure to thrive in FPE. Diagnosis is based on convincing history and resolution of symptoms with food avoidance; confirmatory diagnostic testing other than food challenge is lacking. The mainstay of management is avoidance of the suspected inciting food, with interval challenge to assess for resolution, which usually occurs in the first years of life. Studies published in the past few years clarify common presenting features, report additional culprit foods, address potential biomarkers, and suggest new management strategies. Keywords Food protein-induced enterocolitis. Food protein-induced allergic proctocolitis. Allergic enterocolitis. Allergic proctocolitis. Allergic colitis. Food protein-induced enteropathy. Food allergy. FPIAP. FPE. FPIES This article is part of the Topical Collection on Food Allergy
Animal sensitization is a major determinant of asthma in children. Component-resolved studies of ... more Animal sensitization is a major determinant of asthma in children. Component-resolved studies of unselected pediatric populations are lacking. The aim was to describe sensitization to animal components and the association with asthma and rhinitis in animal-sensitized schoolchildren. A random sample of 696 children (11-12 years) from a Swedish population-based cohort was tested for sensitization to cat, dog, and horse dander using ImmunoCAP. Sera from animal-sensitized children were further analyzed by microarray including three allergen components from cat, four from dog, and two from horse. The parents completed an expanded ISAAC questionnaire. Of 259 animal-sensitized children (≥0.1 kUA /l), 51% were sensitized to all three, 23% to two, and 25% to one species. Current asthma and asthma symptoms following contact with cats were associated with co-sensitization to Fel d 1 and Fel d 4. This association was seen already at moderate-level sensitization (1-15 ISU) to Fel d 4, at which level most children were sensitized to Fel d 1, as well. In dog-sensitized children, the majority was sensitized to more than one dog component, and co-sensitization to Can f 5 and Can f 1/f 2 conferred the greatest risk for asthma. Sensitization to the highly cross-reactive serum albumins was uncommon and not associated with asthma. Among schoolchildren in northern Sweden, where mite allergy is uncommon, furry animals were the primary perennial sensitizers. Asthma was associated with higher levels of component sensitization, and sensitization to more than one component from the same animal conferred the greatest risk.
Background: Few population-based cohort studies have examined reported food hypersensitivity long... more Background: Few population-based cohort studies have examined reported food hypersensitivity longitudinally. We investigated prevalence, incidence and remission of perceived food hypersensitivity among schoolchildren from 8 to 12 years of age, and risk factors associated with incidence and remission. Methods: A population-based cohort including all 7-8 year-old children in three Swedish towns was recruited in 2006. A total of 2,585 (96% of invited) children participated in a parental questionnaire. The children in two of the towns, n = 1,700 (90% of invited) also participated in skin-prick-testing with airborne allergens. The cohort was followed using the same methods at 11-12 years of age. At study follow up, specific IgE to foods was analyzed in a randomized subset of children (n = 652). Results: The prevalence of perceived food hypersensitivity increased from 21% at 8 years to 26% at 12 years of age. During this four-year-period, the cumulative incidence of food hypersensitivity was high (15%), as was remission (33%). This pattern was particularly evident for hypersensitivity to cow´s milk, while the incidence of hypersensitivity to other foods was lower. Female sex, allergic heredity, current rhinitis and allergic sensitization were associated with the incidence of food hypersensitivity and allergic sensitization was negatively associated with remission. Risk-factor-patterns for both incidence and remission were different for hypersensitivity to milk compared with hypersensitivity to other foods. Generally, the agreement between reported food hypersensitivity and IgE-sensitization to the implicated food was poor. Conclusions: In this longitudinal, population-based cohort-study perceived food hypersensitivity was common among children between ages 8 and 12, often transient and not well correlated with food-specific IgE. While these findings suggest an overestimated prevalence of food hypersensitivity, the public-health-significance remains high as they reflect the perceived reality to which the children adapt their life and food intakes.
Furry animal sensitisation to allergen components and asthma diagnosis in a child cohort from nor... more Furry animal sensitisation to allergen components and asthma diagnosis in a child cohort from northern Sweden
The Journal of Allergy and Clinical Immunology, Feb 1, 2015
RATIONALE: Atopic sensitization increases the risk of asthma. Our aim was to investigate patterns... more RATIONALE: Atopic sensitization increases the risk of asthma. Our aim was to investigate patterns of sensitization to allergens and allergen components in relation to asthma among adults in a Swedish populationbased sample. METHODS: A questionnaire targeting asthma was sent to 30 000 randomly selected adults (16-75 y) in west Sweden. Of the 18 087 responders, a randomly selected sample of 2000 subjects and in addition all 1536 subjects reporting asthma were invited to clinical examinations. Sera were received from 906 subjects with asthma and from 1000 without reported asthma (controls) and were tested for three IgE panels of inhalant and food allergens. Samples with a level of IgE >0.35 kU A /l were further analyzed for IgE against each individual allergen and nine allergen components related to furry animals. RESULTS: The risk of being sensitized to any of the 21 tested allergens was significantly higher in the asthma group. The risk was highest for individuals sensitized to furry animals (risk ratios 4,5-7,9). The level of IgE to animal allergens was also significantly higher in the asthma group. Cosensitization to more than one cat and/or dog allergen component conferred a greater risk for asthma. Simultaneous sensitization to the cat allergens Fel d 1 and Fel d 4 was associated with asthma. CONCLUSIONS: In this large population-based study subjects with asthma were commonly co-sensitized to more than one animal allergen component, especially to Fel d 1 and Fel d 4. Component-resolved analysis has the potential to increase precision when assessing asthma in adults.
To cite this article: Winberg A, Nordström L, Strinnholm Å, Nylander A, Jons€ all A, Rönmark E, W... more To cite this article: Winberg A, Nordström L, Strinnholm Å, Nylander A, Jons€ all A, Rönmark E, West CE. New validated recipes for double-blind placebo-controlled lowdose food challenges.
Background: There is need for prognostic markers for symptomatic food allergy since current diagn... more Background: There is need for prognostic markers for symptomatic food allergy since current diagnostic methods are insufficient and/or time and labor consuming. Objective: To estimate the cytokine mRNA profiles in peripheral blood mononuclear cells (PBMC) before and after a double-blind placebo-controlled food challenge series in schoolchildren with suspected allergy to milk, egg or cod and in healthy controls. Analyses of fecal inflammatory biomarkers before and after the challenge were included. Methods: Twelve-year-old children from a population-based cohort reporting complete avoidance of milk, egg, cod or wheat due to perceived hypersensitivity were clinically examined and those with suspected food allergy were evaluated with a 3-session double-blind placebo-controlled food challenge (n = 18). Seven healthy controls participated in a double-blind challenge with egg. Before and after the challenge series, the cytokine mRNA expression was quantified for 13 cytokines discriminating between humoral Th2-, cytotoxic Th1-, regulatory Th3/Tr1-and inflammatory responses. Fecal calprotectin and eosinophil-derived neurotoxin (EDN) were also analyzed in children with suspected food allergy before and after the challenge series. Results: Pre challenge, children with suspected food allergy had higher IL-13 and TNF-a expression and lower IFN-c and IL-15 expression compared to healthy controls (all p < 0.05). Children with challengeproven food allergy had increased IL13 and IL-10 expression compared to the levels seen in negative challenges (p < 0.05). Post challenge, IL-1b and IL-6 mRNA levels were elevated in the food allergic children compared to controls (p < 0.05). Fecal calprotectin and EDN levels were higher in challenge-proven food allergy compared to a negative challenge although not statistically significantly. Conclusion & clinical relevance: Increased baseline mRNA levels of the Th2-related cytokine IL-13 and the regulatory cytokine IL-10 predicted a positive food challenge outcome. These cytokines in combination with fecal calprotectin and EDN might serve as future prognostic markers for symptomatic, IgEmediated food allergy but need further validation in a larger patient cohort.
Article type : Regular Article 10-year review found increasing incidence trends of emergency egg ... more Article type : Regular Article 10-year review found increasing incidence trends of emergency egg allergy reactions and food induced anaphylaxis in children
Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is i... more Objectives Knowledge about the prevalence of allergies to foods in childhood and adolescence is incomplete. The purpose of this study was to investigate the prevalence of allergies to milk, egg, cod, and wheat using reported data, clinical examinations, and double-blind placebocontrolled food challenges, and to describe the phenotypes of reported food hypersensitivity in a cohort of Swedish schoolchildren. Methods In a population-based cohort of 12-year-old children, the parents of 2612 (96% of invited) completed a questionnaire. Specific IgE antibodies to foods were analyzed in a random sample (n=695). Children reporting complete avoidance of milk, egg, cod, or wheat due to perceived hypersensitivity and without physician-diagnosed celiac disease were invited to undergo clinical examination that included specific IgE testing, a celiac screening test, and categorization into phenotypes of food hypersensitivity according to preset criteria. Children with possible food allergy were further evaluated with double-blind challenges. Results In this cohort, the prevalence of reported food allergy to milk, egg, cod, or wheat was 4.8%. Food allergy was diagnosed in 1.4% of the children after clinical evaluation and in 0.6% following double-blind placebo-controlled food challenge. After clinical examination, children who completely avoided one or more essential foods due to perceived food hypersensitivity were categorized with the following phenotypes: allergy (29%), outgrown allergy (19%), lactose intolerance (40%), and unclear (12%). Conclusions There was a high discrepancy in the prevalence of allergy to milk, egg, cod and wheat as assessed by reported data, clinical evaluation, and double-blind food challenges. Food
Background During several decades the prevalence of atopic dermatitis (AD) has increased and now ... more Background During several decades the prevalence of atopic dermatitis (AD) has increased and now affects about one fifth of all children in high-income countries. While the increase continues in lower income countries, the AD prevalence might have reached a plateau in high-income countries. Objectives The aim of this study was to investigate trends in prevalence of AD and atopic comorbidity among schoolchildren in Sweden. Methods The study population consisted of three cohorts of children in Norrbotten, Sweden, from 1996 (n=3430), 2006 (n=2585), and 2017 (n=2785), median age 8 years. A questionnaire was used, including questions from the ISAAC protocol, identical in all three cohorts. Trends in prevalence of AD was estimated, as well as trends in atopic comorbidity. Prevalence was estimated both according to the ISAAC definition of AD, and by adding reported diagnosis by a physician (D-AD). Results The prevalence of AD decreased in the last decade, from 22.8 % (1996) and 21,3 % (200...
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