Potential links between the emerging risk factors for food allergy and vitamin D status.

A variety of hypotheses have been proposed to explain the recently described increase in food allergy among children living in developed countries. In this study, we summarize the emerging risk factors for IgE-mediated food allergy in early life, and then review the evidence for and against an association between low vitamin status (VDS) and food allergy. We consider whether each of the epidemiological variables that have been associated with food allergy may also be associated with VDS; and argue that future studies must adequately account for the potential relationships between risk factors for food allergy and VDS, and must also discriminate between vitamin D derived by sun exposure, diet and oral supplementation.

Anxiety is more common in children with asthma.

OBJECTIVE: There are a variety of reasons why there may be an association between asthma and anxiety in children. Research into the relation between asthma and anxiety has been limited by the sole use of parent-reported or self-reported asthma symptoms to define asthma status. The objective of this study was to determine if children with physician-defined asthma are more likely to suffer anxiety than children without asthma. DESIGN: A population-based, cross-sectional assessment, of self-reported anxiety symptoms. SETTING AND PARTICIPANTS: Children aged 5-13 years from Barwon region of Victoria, Australia. Asthma status was determined by review with a paediatrician. Controls were a sample of children without asthma symptoms (matched for age, gender and school). OUTCOME MEASURE: The Spence Children's Anxiety Scale (SCAS) written questionnaire. The authors compared the mean SCAS score, and the proportion of children with an SCAS score in the clinical range, between the groups. RESULTS: Questionnaires were issued to 205 children with asthma (158 returned, response rate 77%), and 410 controls (319 returned, response rate 78%). The SCAS scores were higher in asthmatics than controls (p<0.001); and were more likely to be in the clinical range (OR=2.5, 95% CI 1.1 to 5.8, p=0.036). There was no evidence that these associations could be explained by known confounding factors. CONCLUSIONS: Children with asthma are substantially more likely to suffer anxiety than children without asthma. Future studies are required to determine the sequence of events that leads to this comorbidity, and to test strategies to prevent and treat anxiety among children with asthma.

Parent initiated prednisolone for acute asthma in children of school age: randomised controlled crossover trial.

OBJECTIVE: To evaluate the efficacy of a short course of parent initiated oral prednisolone for acute asthma in children of school age. DESIGN: Double blind, randomised, placebo controlled, crossover trial in which episodes of asthma, rather than participants, were randomised to treatment. SETTING: The Barwon region of Victoria, Australia. PARTICIPANTS: Children aged 5-12 years with a history of recurrent episodes of acute asthma. INTERVENTION: A short course of parent initiated treatment with prednisolone (1 mg/kg a day) or placebo. MAIN OUTCOME MEASURES: The primary outcome measure was the mean daytime symptom score over seven days. Secondary outcome measures were mean night time symptom score over seven days, use of health resources, and school absenteeism. RESULTS: 230 children were enrolled in the study. Over a three year period, 131 (57%) of the participants contributed a total of 308 episodes of asthma that required parent initiated treatment: 155 episodes were treated with parent initiated prednisolone and 153 with placebo. The mean daytime symptom score was 15% lower in episodes treated with prednisolone than in those treated with placebo (geometric mean ratio 0.85, 95% CI 0.74 to 0.98; P=0.023). Treatment with prednisolone was also associated with a 16% reduction in the night time symptom score (geometric mean ratio 0.84, 95% CI 0.70 to 1.00; P=0.050), a reduced risk of health resource use (odds ratio 0.54, 95% CI 0.34 to 0.86; P=0.010), and reduced school absenteeism (mean difference -0.4 days, 95% CI -0.8 to 0.0 days; P=0.045). CONCLUSION: A short course of oral prednisolone initiated by parents when their child experiences an episode of acute asthma may reduce asthma symptoms, health resource use, and school absenteeism. However, the modest benefits of this strategy must be balanced against potential side effects of repeated short courses of an oral corticosteroid. TRIAL REGISTRATION: ISRCTN 26232583.

Microbial exposure, interferon gamma gene demethylation in naïve T-cells, and the risk of allergic disease.

The period of immune programming during early life presents a critical window of opportunity for the prevention of allergic diseases. There is mounting evidence that inappropriate immune programming may involve disruption of specific epigenetic modifications (switches) at immune-related genes. This novel area of research has great potential, as epigenetic changes are known to be sensitive to environmental factors and may therefore provide a mechanistic link for the observed association between specific environmental cues, faulty immune development, and the risk of allergic disease. In addition, the dynamic and potentially reversible nature of epigenetic modifications offers potentially novel targets for therapeutic and/or preventative interventions. We review the evidence that (1) failure to up-regulate the interferon gamma (IFNgamma) response during infancy is an important determinant of the risk of allergic disease, (2) expression of the IFNgamma gene in naïve T-cells is regulated by epigenetic mechanisms, and (3) failure to up-regulate IFNgamma gene expression of naïve T-cells associated with low early life microbial exposure. Taken together, these lines of evidence suggest that low microbial exposure during early life increases the risk of allergic disease by reducing demethylation (activation) of the IFNgamma gene of naive T-cells.

Social consumption of alcohol in adolescents with Type 1 diabetes is associated with increased glucose lability, but not hypoglycaemia.

AIM: To determine the effects of social consumption of alcohol by diabetic adolescents on glycaemic control. METHODS: Fourteen (five male) patients aged > 16 years were recruited from the diabetes clinic at the Royal Children's Hospital. The continuous glucose monitoring system (CGMS) was attached at a weekend when alcohol consumption was planned for one night only. For each patient, the 12-h period from 18.00 h to 06.00 h for the night with alcohol consumption (study period) was compared with the same period with non-alcohol consumption (control period) either 24 h before or after the alcohol study night. Thus, each subject was his/her own control. Glycaemic outcomes calculated from continuous glucose monitoring included mean blood glucose (MBG), percentage of time spent at low glucose levels (CGMS < 4.0 mmol/l), normal glucose levels (CGMS 4.0-10.0 mmol/l) and high glucose levels (> 10.0 mmol/l) and continuous overall net glycaemic action (CONGA). RESULTS: The mean number of standard alcohol drinks consumed during the study period was 9.0 for males and 6.3 for females. There was no difference in percentage of time at high and normal glucose levels in the study and control periods. During the control period, there was a higher percentage of time with low glucose levels compared with the study period (P < 0.05). There was an increased level of glycaemic variation during the study time when compared with the control period. CONCLUSIONS: In an uncontrolled, social context, moderately heavy alcohol consumption by adolescents with Type 1 diabetes appears to be associated with increased glycaemic variation, but not with low glucose levels.