Higher parental education was associated with better asthma control.

AIM: Inhaled corticosteroids have resulted in the improved control of asthma and a reduced need for hospitalisation. This study aimed to examine the prevalence of uncontrolled asthma and factors that affect asthma control. METHODS: The data came from a longitudinal cohort study of children. The parents answered questionnaires from age 6 months to 12 years. The response rate at age 12 years was 76% (3637/4777) and doctor-diagnosed asthma was reported in 6.4% (n = 233). Asthma control was examined with the Asthma Control Test (ACT), where scores below 20 denote uncontrolled asthma. RESULTS: Of the children with asthma at age 12 years, 15% had an ACT value below 20, that is uncontrolled asthma. Independent risk factors for uncontrolled asthma were wheeze triggered by exercise (adjusted OR, aOR 5.6; 1.9-16.6), cat at home (aOR 3.5; 1.2-10.0) and current doctor-diagnosed rhinitis (aOR 2.8; 95% CI 1.1-7.0). A higher education in the parents reduced the risk of uncontrolled asthma (aOR 0.3; 95% CI 0.1-0.8). Only six children (i.e. 2.6%) reported hospitalisation due to asthma during the last year. CONCLUSION: Of the children with asthma, 15% had uncontrolled asthma. Higher education in the parents was associated with better asthma control in the children.

Eating fish and farm life reduce allergic rhinitis at the age of twelve.

BACKGROUND: The prevalence of allergic rhinitis has increased, but the cause of this rise is partly unknown. Our aim was to analyse the prevalence, risk factors, and protective factors for allergic rhinitis in 12-year-old Swedish children. METHODS: Data were collected from a prospective, longitudinal cohort study of children born in western Sweden in 2003. The parents answered questionnaires when the children were 6 months to 12 years. The response rate at 12 years was 76% (3637/4777) of the questionnaires distributed. RESULTS: At the age of 12, 22% of children had allergic rhinitis and 57% were boys. Mean age at onset was 7.8 years, and 55% reported their first symptoms after 8 years. The most common trigger factors were pollen (85%), furry animals (34%), and house dust mites (17%). A multivariate analysis showed that the adjusted odds ratios and 95% confidence intervals for the independent risk factors for allergic rhinitis at 12 were as follows: parental allergic rhinitis (2.32, 1.94-2.77), doctor-diagnosed food allergy in the first year (1.75, 1.21-2.52), eczema in the first year (1.61, 1.31-1.97), and male gender (1.25, 1.06-1.47). Eating fish once a month or more at age of 12 months reduced the risk of allergic rhinitis at 12 years of age (0.70, 0.50-0.98) as did living on a farm with farm animals at 4 years (0.51, 0.32-0.84). Continuous farm living from age 4 to 12 seemed to drive the association. CONCLUSIONS: Allergic rhinitis affected > 20% of 12-year-olds, but was lower in children who ate fish at 12 months or grew up on a farm with farm animals.

Methyl-cellulose powder for prevention and management of nasal symptoms.

INTRODUCTION: HPMC-p, an inert micronized powder form of hydroxy-propyl-methyl-cellulose, when insufflated nasally, provides a natural barrier against pollen allergens and noxious agents. This overview assesses the efficacy and safety of this patented powder product and delivery system without an analogue among the cellulose derivatives. Areas covered: Twenty-six studies with HPMC-p were critically appraised to obtain an updated characteristic of the product. Most studies assessed the efficacy of HPMC-p as a nasal barrier enforcing measure: one experimental setup evaluated its ability to prevent or delay the diffusion of allergen through it, two clinical studies used allergen provocation tests, and the remaining relied on clinical criteria in open real world or placebo controlled designs. Two studies checked if HPMC-p could enhance the efficacy of drugs applied nasally to treat local symptoms. The studies, using either nasal allergen challenge or natural exposure of patients to environmental allergen, support the hypothesis that HPMC-p possesses barrier enforcing properties. Also, acute and clinical experiments indicated that intra-nasal application of HPMC-p following local relief medications enhances their ability to suppress symptoms and reduces their long-term use. Expert commentary: Nasal insufflation of HPMC-p provides a mucosal barrier, reducing the nasal symptoms and enhancing the effects of local relief medications.

Allergic rhinoconjunctivitis continued to increase in Swedish children up to 2007, but asthma and eczema levelled off from 1991.

AIM: This study investigated whether allergies among schoolchildren increased in Sweden between 1979 and 2007 and whether the geographical differences observed in previous studies remained. METHODS: We collected questionnaire data on asthma, allergic rhinoconjunctivitis (ARC) and eczema in children aged seven to eight years from Mölndal, Gothenburg, in south-western Sweden and Kiruna in northern Sweden in 1979 (n = 4682), 1991 (n = 2481) and 2007 (n = 1029). The same regions and questions were used in all three studies, and extra questions on food allergy or intolerance were added in 2007. RESULTS: In 1979, 1991 and 2007, the total prevalence of asthma was 2.5%, 5.7% and 7.1%, ARC was 5.5%, 8.1% and 11.1% and eczema was 7.1%, 18.3% and 19.7%, respectively. Asthma prevalence remained higher in Kiruna, but no significant regional differences were seen for ARC and eczema. Almost 20% reported a history of food allergy or intolerance, with a higher prevalence in Kiruna. The allergy risk was reduced if both parents were born outside Sweden. CONCLUSION: The prevalence of ARC continued to increase between 1991 and 2007, but increases in asthma and eczema started to level off in 1991. Some geographical differences remained, but total allergy rates were similar in Kiruna and Mölndal in 2007.

The allergic march comprises the coexistence of related patterns of allergic disease not just the progressive development of one disease.

AIM: This study explored the development and comorbidity of allergic diseases by analysing the relationship between allergic manifestations in infancy and at the age of 8. METHODS: We included 5654 children born in Sweden in 2003 in a longitudinal study. Parents answered postal questionnaires when the children were six months and one, four-and-a-half and eight years of age. RESULTS: The response rate at eight years was 4051 (71.6%), and we analysed 3382 children with complete data. The number of manifestations in infancy increased the risk of allergic disease at eight years of age: 72% of children with one early manifestation were symptom free at 8, compared to 45% with two or more manifestations. Similar manifestations occurred in infancy and at the age of 8, for example recurrent wheeze increased the risk of doctor-diagnosed asthma by an adjusted odds ratio of 6.5. Eczema and food allergy independently increased the risk of all four allergic manifestations at eight years. CONCLUSION: Allergic disease at the age of 8 was related to the number of allergic manifestations in infancy. Manifestations were similar at both ages, suggesting an allergic march with the coexistence of disease patterns rather than the progressive development of one disease.

A persistently high body mass index increases the risk of atopic asthma at school age.

AIM: Being overweight has been associated with the risk of developing childhood asthma, but studies have produced conflicting results, for example with regard to possible links to allergic diseases. This study aimed to explore the relationship between body mass index (BMI) and school-age asthma. METHODS: Data were obtained from a prospective, longitudinal study of 5044 children born in western Sweden. The parents answered questionnaires at six months and one, four-and-a-half and eight years of age. The response rate to the final questionnaire at the age of eight was just over 80%. BMI was adjusted for age and gender, and a high BMI was defined as the 85th percentile and above. RESULTS: A multivariate analysis showed an independently increased risk of doctor-diagnosed asthma among children with a persistently high BMI, both in infancy and at school age, with an adjusted odds ratio (aOR) of 2.9 and a 95% confidence interval (CI) of 1.3-6.4. In addition, persistently high BMI was associated with an increased risk of atopic asthma (aOR 4.7, 95% CI 2.0-11.0). CONCLUSION: A persistently high BMI during childhood increased the risk of doctor-diagnosed asthma at school age. The increased risk of atopic asthma suggests an effect mediated via the immune system.

Antibiotics in the first week of life is a risk factor for allergic rhinitis at school age.

BACKGROUND: Heredity as well as external factors influences the development of allergic rhinitis. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at school age. METHODS: This is a prospective, longitudinal study of children born in western Sweden in 2003 where 50% of the birth cohort was randomly selected. The parents answered questionnaires at 6 months, 12 months, 4.5 yr and 8 yr. At 8 yr, 5044 questionnaires were distributed. Of these, 4051 responded, that is, 80.3%. Current allergic rhinitis was defined as symptoms and use of medication during the past 12 months. RESULTS: Current allergic rhinitis at 8 yr was reported by 10.9%. Mean onset age was 5.7 yr, and 61.9% were boys. In a multivariate analysis, antibiotics in the first week of life increased the risk of allergic rhinitis (adjusted odds ratio 1.75, 95% confidence interval (1.03, 2.97)). Increased risk was also seen with parental allergic rhinitis (aOR 2.73 (2.12, 3.52)), food allergy first year (aOR 2.45 (1.61, 3.73)), eczema first year (aOR 1.97 (1.50, 2.59)) and male gender (aOR 1.35 (1.05, 1.74)). Living on a farm at 4.5 yr reduced the risk (aOR 0.31 (0.13, 0.78)). CONCLUSION: Antibiotics in the first week of life increased the risk of allergic rhinitis at school age, while living on a farm at preschool age reduced the risk. Both findings are compatible with the hygiene hypothesis.

A nasally applied cellulose powder in seasonal allergic rhinitis in adults with grass pollen allergy: a double-blind, randomized, placebo-controlled, parallel-group study.

BACKGROUND: A nasally applied cellulose powder is increasingly used in many countries as a remedy for allergic rhinitis. In 2009, a 4-week study in birch pollen-allergic children showed a reduction in nasal symptoms. The best effect occurred on days with lower pollen counts. The present study in grass pollen-allergic adults used the same basic design. METHODS: In May 2013, a double-blind, placebo-controlled study was conducted in 108 patients with allergic rhinitis due to grass pollen (18-40 years of age). SMS on mobile phones were used as reminders of treatment and reporting of symptom scores. RESULTS: We found significant reductions in severity scores for sneezing, runny nose, stuffy nose and symptoms from eyes and lower airways, both separately and together (all p < 0.001). Reflective opinion of effect and guess on treatment at follow-up visits (both p < 0.001) confirmed a high efficacy. No clinically significant adverse effects were reported. CONCLUSIONS: The product provided significant protection against all seasonal allergic rhinitis symptoms from both upper and lower airways during the grass pollen season in an adult population. The magnitude and scope of efficacy support the use of the product as an early choice in the treatment of allergic rhinitis.

Toxin-producing Clostridium difficile strains as long-term gut colonizers in healthy infants.

Clostridium difficile is a colonizer of the human gut, and toxin-producing strains may cause diarrhea if the infectious burden is heavy. Infants are more frequently colonized than adults, but they rarely develop C. difficile disease. It is not known whether strains of C. difficile differ in the capacity to colonize and persist in the human gut microbiota. Here, we strain typed isolates of C. difficile that had colonized 42 healthy infants followed from birth to ≥12 months of age by using PCR ribotyping of the 16S-23S rRNA intergenic spacer region. The isolates were also characterized regarding carriage of the toxin genes tcdA, tcdB, and cdtA/B and the capacity to produce toxin B in vitro. Most strains (71%) were toxin producers, and 51% belonged to the 001 or 014 ribotypes, which often cause disease in adults. These ribotypes were significantly more likely than others to persist for ≥6 months in the infant micobiota, and they were isolated from 13/15 children carrying such long-term-colonizing strains. Ribotype 001 strains were often acquired in the first week of life and attained higher population counts than other C. difficile ribotypes in newborn infants' feces. Several toxin-negative ribotypes were identified, two of which (GI and GIII) were long-term colonizers, each found in one infant. Our results suggest that the toxin-producing C. difficile ribotypes 001 and 014 have special fitness in the infantile gut microbiota. Toxin-producing strains colonizing young children for long time periods may represent a reservoir for strains causing disease in adults.

Pacifier cleaning practices and risk of allergy development.

OBJECTIVE: Immune stimulation through exposure to commensal microbes may protect against allergy development. Oral microbes may be transferred from parents to infants via pacifiers. We investigated whether pacifier cleaning practices affected the risk of allergy development. METHODS: A birth-cohort of 184 infants was examined for clinical allergy and sensitization to airborne and food allergens at 18 and 36 months of age and, in addition, promptly on occurrence of symptoms. Pacifier use and pacifier cleaning practices were recorded during interviews with the parents when the children were 6 months old. The oral microbiota of the infants was characterized by analysis of saliva samples collected at 4 months of age. RESULTS: Children whose parents "cleaned" their pacifier by sucking it (n = 65) were less likely to have asthma (odds ratio [OR] 0.12; 95% confidence interval [CI] 0.01-0.99), eczema (OR 0.37; 95% CI 0.15-0.91), and sensitization (OR 0.37; 95% CI 0.10-1.27) at 18 months of age than children whose parents did not use this cleaning technique (n = 58). Protection against eczema remained at age 36 months (hazard ratio 0.51; P = .04). Vaginal delivery and parental pacifier sucking yielded independent and additive protective effects against eczema development. The salivary microbiota differed between children whose parents cleaned their pacifier by sucking it and children whose parents did not use this practice. CONCLUSIONS: Parental sucking of their infant's pacifier may reduce the risk of allergy development, possibly via immune stimulation by microbes transferred to the infant via the parent's saliva.

Early fish introduction and neonatal antibiotics affect the risk of asthma into school age.

BACKGROUND: The early introduction of fish has been reported to reduce the risk of wheezing disorder in early childhood, while broad-spectrum antibiotics in the first week have been associated with an increased risk. However, it is uncertain whether the effects remain into school age. The aim was to explore these risk factors for doctor-diagnosed asthma at 8 years. METHODS: Data were obtained from a prospective, longitudinal study of a cohort of children born in western Sweden. The parents answered questionnaires at 6 months and 1, 4.5 and 8 years of age. The response rate at 8 years was 80% of the questionnaires distributed (4051/5044), that is, 71% of the families entering the study (4051/5654). RESULTS: At 8 years, 5.7% reported current doctor-diagnosed asthma. Of these, 65% had atopic asthma and 35% non-atopic asthma. In the multivariate analysis, atopic heredity, male gender and own allergic disease during infancy were risk factors for doctor-diagnosed asthma at 8 years. In addition, the introduction of fish before the age of 9 months independently reduced the risk (adjusted OR 0.6; 95% CI 0.4-0.96), while broad-spectrum antibiotics in the first week independently increased the risk of current asthma at school age (aOR 2.3; 1.2-4.2). Regarding types of asthma, the effects were significant in atopic asthma but not in non-atopic asthma. CONCLUSION: The early introduction of fish and neonatal antibiotic treatment influence the risk of asthma into school age. The significant effect on atopic asthma is of particular importance, as this phenotype is of major clinical significance.

The heterogeneity of asthma phenotypes in children and young adults.

Objective. Genetic heterogeneity and risk factor distribution was analyzed in two previously proposed asthma phenotypes. Method. A sample of 412 subjects was investigated at 7-8, 12-13, and 21-22 years of age with questionnaires, skin prick tests, and genetic analysis of IL-4 receptor (IL4R) single-nucleotide polymorphisms. The sample was subdivided in one group with no asthma, and two groups with asthma separated by age of onset of symptoms, namely, early onset asthma (EOA) and late onset asthma (LOA). Risk factors and IL4R markers were analyzed in respect to asthma phenotypes. Results. EOA and LOA groups were both associated with atopy and a maternal history of asthma. Female gender was more common in LOA, whereas childhood eczema, frequent colds in infancy, and a paternal history of asthma were more common in EOA. The AA genotype of rs2057768 and the GG genotype of rs1805010 were more common in LOA, whereas the GG genotype of rs2107356 was less common in EOA. Conclusion. Our data suggest that early and late onset asthma may be of different endotypes and genotypes.

Adhesin and superantigen genes and the capacity of Staphylococcus aureus to colonize the infantile gut.

Staphylococcus aureus is a pathogen and a skin commensal that is today also common in the infant gut flora. We examine the role of S. aureus virulence factors for gut colonization. S. aureus isolated from quantitative stool cultures of 49 Swedish infants followed from birth to 12 months of age were assessed for 30 virulence-associated genes, spa type, and agr allele by serial polymerase chain reaction (PCR) assays. Strains carrying genes encoding collagen-binding protein, and the superantigens S. aureus enterotoxin O/M (SEO/SEM) had higher stool counts than strains lacking these genes, whereas genes for S. aureus enterotoxin A (SEA) were associated with low counts. A cluster of strains belonging to agr allele I and the spa clonal cluster 630 (spa-CC 630) that carried genes encoding SEO/SEM, SEC, collagen-binding protein, and elastin-binding protein were all long-time colonizers. Thus, certain S. aureus virulence factors might promote gut colonization.

Preschool wheeze - impact of early fish introduction and neonatal antibiotics.

AIM: The aim of this study was to analyse the risk factors for preschool wheeze with special reference to the early introduction of fish and early antibiotic treatment. To avoid reverse causation regarding antibiotics, we focused on the influence of broad-spectrum antibiotics given during the first week of life. METHODS: Data were obtained from a prospective, longitudinal study of a cohort of children born in western Sweden where 50% of the birth cohort was randomly selected. The parents answered questionnaires at 6 and 12 months and at 4.5 years of age. The response rate at 4.5 years was 83% (4496 of 5398 questionnaires distributed). RESULTS: In the multivariate analysis, broad-spectrum antibiotics in the first week increased the risk of recurrent wheeze (≥ 3 episodes) during the last 12 months at age 4.5 years (adjusted OR 2.2; 95% CI 1.3-3.8) and multiple-trigger wheeze (aOR, 2.8; 1.3-6.1). The introduction of fish before the age of 9 months reduced the risk of recurrent wheeze (aOR, 0.6; 0.4-0.8). CONCLUSION: Treatment with broad-spectrum antibiotics during the first week of life increased the risk of recurrent wheeze and multiple-trigger wheeze at preschool age. The early introduction of fish reduced the risk of recurrent wheeze.

A nasally applied cellulose powder in seasonal allergic rhinitis (SAR) in children and adolescents; reduction of symptoms and relation to pollen load.

BACKGROUND: A nasally applied cellulose powder is increasingly used in many countries as a remedy for allergic rhinitis. The absence of side effects makes the treatment particularly attractive in children. The efficacy in pollen allergic children, however, is not studied, nor is the relation to various pollen exposures. METHODS: During the birch pollen season in 2009, a double blind, placebo-controlled study was conducted in 53 subjects, aged 8-18 yr, with allergic rhinitis attributed to birch pollen. All children were on daily oral antihistamine. Reminders and reporting of symptom scores were made by SMS on mobile phones. Pollen was collected in a volumetric trap from which figures of pollen concentrations from 1979 to 2009 were available. RESULTS: There was a significant reduction in total symptom scores from the nose (Placebo 7.29, Active 6.07, p = 0.033) and specifically for running nose (Placebo 2.56, Active 2.03, p = 0.017). All symptoms from the nose, eyes and lower airways were lower in the active group but reached significance only as earlier. The best effect was seen after days with low or moderate pollen counts (≤100/m(3)), the predominating pollen load over 31 yr in the area. No clinically significant adverse effects were seen. CONCLUSIONS: The product reduces symptoms of SAR in children and adolescents. Original data on pollen concentrations over 31 yr are presented with levels mainly in the low range favouring the observed efficacy profile. SMS communication on mobile phone for reminders and recording symptom scores was an excellent logistics tool.

Early protective and risk factors for allergic rhinitis at age 4½ yr.

Allergic heredity plays a major role in the development of allergic rhinitis. In addition the introduction of food may influence the risk of subsequent allergic disease. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at preschool age. Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003 and 8,176 families (50% of the birth cohort) were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4½ yr of age. The response rate at 4½ yr was 4,496, i.e. 83% of the 5,398 questionnaires distributed at 4½ yr. At 4½ yr of age, 5.5% reported symptoms of allergic rhinitis during the last year. In the multivariate analysis, independent risk factors for allergic rhinitis were: allergic sensitisation to food allergens at 4½ yr (OR 10.21; 95% confidence interval 4.22-24.73), recurrent wheeze at 4½ yr (3.33; 1.56-7.10), doctor-diagnosed eczema at 4½ yr (2.72; 1.62-4.55), parental rhinitis (2.21; 1.39-3.53), eczema first year (1.97; 1.19-3.26) and male gender (1.82; 1.13-2.94). The risk was reduced with fish introduction before 9 months (0.49; 0.29-0.82). In conclusion, we found that previous and present allergic disease, heredity and male gender increased the risk of allergic rhinitis at 4½ yr of age. The introduction of fish before the age of 9 months reduced the risk.