| 1. |
- af Klinteberg, Maja, 1980-, et al.
(author)
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Decreasing prevalence of atopic dermatitis in Swedish schoolchildren : three repeated population-based surveys
- 2024
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In: British Journal of Dermatology. - : Oxford University Press. - 0007-0963 .- 1365-2133. ; 190:2, s. 191-198
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Journal article (peer-reviewed)abstract
- Background: The prevalence of atopic dermatitis (AD) has increased over several decades and now affects about one-fifth of all children in high-income countries (HICs). While the increase continues in lower-income countries, the prevalence of AD might have reached a plateau in HICs.Objectives: To investigate trends in the prevalence of AD and atopic comorbidity in schoolchildren in Sweden.Methods: The study population consisted of three cohorts of children (median age 8 years) in Norrbotten, Sweden, for 1996 (n = 3430), 2006 (n = 2585) and 2017 (n = 2785). An identical questionnaire that included questions from the International Study of Asthma and Allergies in Childhood (ISAAC) protocol was used in all three cohorts. Trends in AD prevalence were estimated, as well as trends in atopic comorbidity. AD prevalence was estimated both according to the ISAAC definition of AD and by adding the reported diagnosis by a physician (D-AD).Results: The prevalence of AD decreased in the last decade, from 22.8% (1996) and 21.3% (2006) to 16.3% (2017; P < 0.001). The prevalence of D-AD was lower, but the same pattern of decrease was seen, from 9.3% (1996) and 9.4% (2006) to 5.7% (2017; P < 0.001). In all three cohorts, AD was more common among girls than boys (18.9% vs. 13.8% in 2017; P < 0.001). Children from the mountain inlands had a higher prevalence of AD than children from coastal cities (22.0% vs. 15.1% in 2017; P < 0.001). In comparing D-AD, there were no significant differences between the sexes or between inland or coastal living. Concomitant asthma increased over the years from 12.2% (1996) to 15.8% (2006) to 23.0% (2017; P < 0.001). Concomitant allergic rhinitis and allergic sensitization increased from 1996 (15.0% and 27.5%) to 2006 (24.7% and 49.5%) but then levelled off until 2017 (21.0% and 46.7%).Conclusions: The prevalence of AD among schoolchildren in Sweden decreased over the study period, whereas atopic comorbidity among children with AD increased. Although a decrease was seen, AD is still common and the increase in atopic comorbidity among children with AD, especially the increase in asthma, is concerning.
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| 2. |
- Bunne, Joakim, et al.
(author)
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The Majority of Children Sensitized Before School-Age Develop Allergic Disease Before Adulthood: A Longitudinal Population-Based Study
- 2022
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In: Journal of Allergy and Clinical Immunology: In Practice. - : Elsevier BV. - 2213-2198 .- 2213-2201. ; 10:2
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Journal article (peer-reviewed)abstract
- Background: Allergic sensitization increases the risk of 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 1 and 2 (median age, 8 years) in 2 municipalities in Northern Sweden were invited to undergo skin prick tests and answer a questionnaire about allergic diseases, and 88% participated. At ages 12 and 19 years, the protocol was repeated, and 1510 individuals participated in all 3 examinations. Specific IgE data were collected in a random sample at age 19 years (n = 770). Onset of sensitization was defined: 8 years or less, 8 to 12 years, 12 to 19 years, and never sensitized. Adjusted Poisson regression was used to calculate risk ratios (RRs). Results: At 19 years, those sensitized at 8 years of age or earlier had the highest risk of asthma (RR, 4.68; 95% CI, 3.15-6.97) and rhinitis (RR, 22.3; 95% CI, 13.3-37.6), and 84% had developed either asthma or rhinitis. The combination of sensitization at age 8 years or earlier and family history of allergic diseases rendered high risks for asthma (RR, 10.6; 95% CI, 6.71-16.7) and rhinitis (RR, 36.3; 95% CI, 18.9-69.7). Individuals sensitized at age 8 years or earlier showed significantly highest level of sensitization, as judged by number of positive skin test results and titers of specific IgE. Conclusions: Most individuals with sensitization at age 8 years or earlier developed asthma or rhinitis before young adulthood. The high level of sensitization in those sensitized early contributes to the high incidence of allergic airway conditions. © 2021 The Authors
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| 3. |
- Hedman, Linnea, 1979-, et al.
(author)
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Diagnostic intervention improved health-related quality of life among teenagers with food allergy
- 2024
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 19:1 January
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Journal article (peer-reviewed)abstract
- Objectives: The aim was to examine if a diagnostic intervention set up to assess current food allergy to cow’s milk, hen’s egg, fish, or wheat among teenagers had an impact on generic and disease specific health-related quality of life (HRQL). The study compared HRQL scoring before and two years after the intervention, and in relation to age matched controls without reported food allergy.Methods: The study was performed within the Obstructive Lung Disease in Northern Sweden (OLIN) studies where a cohort study on asthma and allergic diseases among 8-year-old schoolchildren was initiated in 2006. At age 12 years, the 125/2612 (5%) children who reported allergy to cow’s milk, hen’s egg, fish, or wheat were invited to a diagnostic intervention including clinical examination, blood tests and evaluation by a pediatric allergist. Of 94 participants, 79 completed generic and disease specific HRQL questionnaires. Additionally, a random sample of 200 (62% of invited) children without food allergy from the OLIN cohort answered the generic HRQL questionnaire. The respondents of the HRQL questionnaires were reexamined two years later and 57 teenagers with and 154 without reported allergy participated.Results: There were no significant differences in generic HRQL scores between teenagers with and without reported food allergy at study entry, or after the intervention. Among those with reported food allergy, we found a significant improvement in disease specific HRQL after the intervention (mean values: 3.41 vs 2.80, p<0.001). Teenagers with only food allergy had better disease specific HRQL compared to those with one, two or three concomitant allergic diseases, both before and after the intervention. Children with only food allergy significantly improved their HRQL after the intervention, 1.84 vs. 2.87 (p<0.001) but this association was not seen in children with one other allergic disorder (3.16 vs. 3.65, p = 0.121) or those with two or more allergic disorders (3.72 vs. 3.90, p = 0.148).Conclusion: The diagnostic intervention showed a long-term improvement of disease specific HRQL but not generic HRQL.
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| 4. |
- Hedman, Linnea, 1979-, et al.
(author)
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Is asthma in children still increasing? : 20-year prevalence trends in northern Sweden
- 2024
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In: Pediatric Allergy and Immunology. - : John Wiley & Sons. - 0905-6157 .- 1399-3038. ; 35:4
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Journal article (peer-reviewed)abstract
- Background: In the present study, we describe prevalence trends of asthma and investigate the association with asthma symptoms, use of asthma medication, and asthma severity among 8-year-old children in Norrbotten, Sweden in 1996, 2006, and 2017.Methods: Within the Obstructive Lung Disease in Northern Sweden (OLIN) studies, three pediatric cohorts were recruited in 1996, 2006, and 2017 respectively. Identical methods were used; all children in first and second grade (median age 8 years) in three municipalities were invited to a parental questionnaire survey, completed by n = 3430 in 1996 (97% participation), n = 2585 in 2006 (96%), and n = 2785 in 2017 (91%). The questionnaire included questions about respiratory symptoms and diagnosis, treatment, and severity of asthma.Results: The prevalence of wheezing was stable during the study, 10.1% in 1996; 10.8% in 2006; and 10.3% in 2017, p =.621, while physician-diagnosed asthma increased: 5.7%, 7.4%, and 12.2%, p <.001. The use of asthma medication in the last 12 months increased: 7.1%, 8.7%, and 11.5%, p <.001. Among children diagnosed with asthma, the prevalence of asthma symptoms, the impact on daily life, and severe asthma decreased, while the use of inhaled corticosteroids increased from 1996 until 2017.Conclusion: The prevalence of wheezing was stable among 8-year-old in this area from 1996 to 2017, while the prevalence of physician-diagnosed asthma doubled but without an increase in asthma morbidity. The increase of physician-diagnosed asthma without a coincident increase in asthma morbidity can partly be explained by more and earlier diagnosis among those with mild asthma.
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| 5. |
- Rönmark, Eva, et al.
(author)
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Prevalence and risk factors for allergic sensitization : 3 cross-sectional studies among schoolchildren from 1996 to 2017
- 2023
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In: Journal of Allergy and Clinical Immunology: Global. - : Elsevier. - 2772-8293. ; 2:4
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Journal article (peer-reviewed)abstract
- Background: The prevalence of allergic sensitization and allergic diseases has increased for decades in Northern Europe, but recent studies are lacking.Objective: We sought to study the prevalence trends of allergic sensitization, associated risk factors, and the association with asthma and allergic rhinitis (AR) among children in Northern Sweden.Methods: Three cohorts of children aged 7 to 8 years participated in a skin prick test (SPT) with 10 airborne allergens in 1996, 2006, and 2017, with 2148, 1693, and 1762 participants tested, respectively, representing 87% to 90% of schoolchildren in the catchment communities. Adjusted Poisson regression was used to identify risk factors for allergic sensitization and the association with asthma and AR.Results: The prevalence of any positive SPT response increased from 21% in 1996 to 30% in 2006 and remained at 30% in 2017 (P <.001). Sensitization to cat was the most common for all the years. The risk factor pattern for a positive SPT response was similar in all examinations, with positive and significant associations with a family history of allergy (risk ratio, 1.4-1.5) and negative and significant associations with having a cat at home (risk ratio, 0.7-0.8). The prevalence of physician-diagnosed asthma increased, but the association with allergic sensitization weakened. The opposite trends were found for AR—decreasing prevalence and strengthened association with allergic sensitization.Conclusions: The prevalence of allergic sensitization increased from 1996 to 2006 but plateaued in the next decade, whereas the risk factor pattern remained stable. The diverging trends of associations between allergic sensitization and asthma and AR suggest secular trends in the clinical management of allergic diseases.
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| 6. |
- Winberg, Anna, 1966-, et al.
(author)
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Dynamics of cytokine mRNA expression and fecal biomarkers in school-children undergoing a double-blind placebo-controlled food challenge series
- 2016
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In: Cytokine. - : Elsevier BV. - 1043-4666 .- 1096-0023. ; 88, s. 259-266
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Journal article (peer-reviewed)abstract
- 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 Thl-, 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-alpha expression and lower IFN-gamma and IL-15 expression compared to healthy controls (all p < 0.05). Children with challenge proven food allergy had increased IL13 and IL-10 expression compared to the levels seen in negative challenges (p < 0.05). Post challenge, IL-1 beta 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.
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| 7. |
- Winberg, Anna, 1966-
(author)
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Epidemiology of food hypersensitivity in school children : validation with double-blind placebo-controlled food challenges and biomarkers
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Background: This thesis focuses on the incidence and remission of reported food hypersensitivity in schoolchildren followed from 8 to 12 -years of age and the prevalence of hypersensitivity to milk, egg, cod and wheat among 12-year olds investigated by reported data, clinical investigation and double-blind placebo-controlled food challenges and biomarkers.Methods: The studies are mainly based on a population based cohort recruited in 2006 from three municipalities in Northern Sweden. All children in first and second grade, aged 7-8 years, were invited to a parental questionnaire study and 2585 (96% of invited) participated. The children in two of the municipalities were also invited to a skin prick test with airborne allergens. At age 11-12 years, there was a follow-up of the cohort using the same methods, with the addition of a child interview and assessment of body mass index (BMI).At the follow-up, children who reported milk hypersensitivity were invited to structured interviews and children reporting complete elimination of milk, egg, cod or wheat due to perceived hypersensitivity were invited to a clinical examination and blood sampling. According to test results, the children were categorized into different food hypersensitivity phenotypes according to preset criteria. Children categorized as current food allergy were then invited to further evaluation with a double-blind placebo-controlled food-challenge using newly developed recipes. Before their use, the recipes were successfully validated regarding detectable sensorial differences between the active and placebo substances in a separate cohort of healthy schoolchildren (n=275).Before and after the challenge series blood samples were collected for analyses of cytokine mRNA expression in peripheral blood mononuclear cells including hallmark cytokines for the humoral allergy-promoting T helper (Th) 2 response, cellular cytotoxicity-promoting Th1 response, inflammatory-, and T regulatory responses. Fecal inflammatory biomarkers were also analyzed before and after the challenge series.Results: Reported food hypersensitivity increased from 21% at age 7-8 years to 26% at 11-12 years. There was a high incidence (15%) as well as a high remission (33%) of reported food hypersensitivity. Risk factors associated with incidence and remission were different for milk hypersensitivity and hypersensitivity to foods other than milk. The agreement between reported symptoms to milk, egg, cod, wheat, soy and peanut and sensitization to the culprit food was poor. At 11 to 12-years of age the prevalence of reported allergy to milk, egg, cod or wheat was 4.8% while the allergy prevalence according to clinical evaluation was 1.4%. This figure was further halved when evaluated with double-blind placebo-controlled food challenges.The majority of children with reported allergy to milk, egg, cod and wheat were categorized as other food hypersensitivity phenotypes, the most common being probable lactose intolerance (40%) and outgrown food allergy (19%). Even though reported milk hypersensitivity among the 11-12 year olds was 14.5%, only 3% were categorized as current milk allergy. Current and outgrown milk allergy was associated with other atopic disorders and a lower BMI (OR 0.8, 95% CI 0.80-0.98). Before the challenge series, the mRNA expression of the cytokines IL-13 and IL-10 were higher among children with a positive compared to a negative challenge outcome.Conclusion: Reported food hypersensitivity was common among school children in Northern Sweden and increased from 7-8 years to 11-12 years of age, and both the incidence and remission of reported hypersensitivity was high. There was an 8-fold difference in the prevalence of allergy to milk, egg, cod or wheat when reported data was assessed by clinical examinations and double-blind placebo-controlled food challenges. Allergy to milk, egg, cod and wheat was an uncommon cause of complete avoidance of these foods due to perceived hypersensitivity. Some of the analyzed biomarkers might serve as prognostic markers for symptomatic, IgE-mediated food allergy but need further validation.
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| 8. |
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| 9. |
- Winberg, Anna, 1966-, et al.
(author)
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Milk allergy is a minor cause of milk avoidance due to perceived hypersensitivity among schoolchildren in Northern Sweden
- 2016
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In: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 105:2, s. 206-214
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Journal article (peer-reviewed)abstract
- AIM: We investigated phenotypes of milk hypersensitivity among schoolchildren aged 11-12 in Northern Sweden.METHODS: In a population-based cohort, 1,824 (98%) children aged 11-12 participated in a questionnaire survey, skin prick testing, interviews on food hypersensitivity and assessment of body mass index (BMI). Of the 265 children reporting milk hypersensitivity, milk avoidance and no celiac disease, 236 (89%) participated in a structured interview and blood samples for analyses of milk-specific Immunoglobulin E. The children were then categorised into milk hypersensitivity phenotypes according to preset criteria.RESULTS: In all, 14.5% reported milk hypersensitivity. Of these, 3% were categorised as current milk allergy, 23% as outgrown milk allergy, 40% as probable lactose intolerance and 11% were non-definable. Furthermore, 23% had discontinued their elimination diet. Milk allergy was associated with other atopic disorders and lower BMI, with an odds Ratio of 0.82 and 95% confidence interval of 0.80-0.98. Only 2% had previously undergone an oral challenge.CONCLUSION: The most common symptom phenotypes among Swedish children aged 11-12 with self-reported milk hypersensitivity and milk avoidance, were lactose intolerance and outgrown milk allergy while current milk allergy was uncommon. Children with milk allergy had a lower BMI and most lacked a challenge proven diagnosis.
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| 10. |
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