An Overview of Environmental Risk Factors for Food Allergy

IgE-mediated food allergy is an increasing public health concern in many regions around the world. Although genetics play a role in the development of food allergy, the reported increase has occurred largely within a single generation and therefore it is unlikely that this can be accounted for by changes in the human genome. Environmental factors must play a key role. While there is strong evidence to support the early introduction of allergenic solids to prevent food allergy, this is unlikely to be sufficient to prevent all food allergy. The purpose of this review is to summarize the evidence on risk factors for food allergy with a focus the outdoor physical environment. We discuss emerging evidence of mechanisms that could explain a role for vitamin D, air pollution, environmental greenness, and pollen exposure in the development of food allergy. We also describe the recent extension of the dual allergen exposure hypothesis to potentially include the respiratory epithelial barrier in addition to the skin. Few existing studies have examined the relationship between these environmental factors with objective measures of IgE-mediated food allergy and further research in this area is needed. Future research also needs to consider the complex interplay between multiple environmental factors

The burden of self-reported antibiotic allergies in health care and how to address it: A systematic review of the evidence

Background: Antibiotics are the first-line treatment for bacterial infections; however, overuse and inappropriate prescribing have made antibiotics less effective with increased antimicrobial resistance. Unconfirmed reported antibiotic allergy labels create a significant barrier to optimal antimicrobial stewardship in health care, with clinical and economic implications. Objective: A systematic review was conducted to summarize the impact of patient-reported antibiotic allergy on clinical outcomes and various strategies that have been employed to effectively assess and remove these allergy labels, improving patient care. Methods: The review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A critical appraisal was conducted on all studies and a narrative synthesis was performed to identify themes. Results: Four themes emerged: the prevalence of antibiotic allergy, impact of antibiotic allergy on antimicrobial prescribing, impact of antibiotic allergy on clinical outcomes, and delabeling strategies to improve clinical outcomes. Of the 32 studies, including 1,089,675 participants, the prevalence of reported antibiotic allergy was between 5% and 35%. Patients with a reported antibiotic allergy had poorer concordance with prescribing guidelines in 30% to 60% of cases, with a higher use of alternatives such as quinolone, tetracycline, macrolide, lincosamide, and carbapenem and lower use of beta-lactam antibiotics. Antibiotic allergy delabeling was identified as an intervention and recommendation to advance the state of the science. Conclusions: There is substantial evidence within the literature that antibiotic allergy labels significantly impact patient clinical outcomes and a consensus that systematic assessment of reported antibiotic allergies, commonly referred to as delabeling, improves the clinical management of patients

VITALITY trial: protocol for a randomised controlled trial to establish the role of postnatal vitamin D supplementation in infant immune health

Introduction Postnatal vitamin D supplementation may be associated with a reduction in IgE-mediated food allergy, lower respiratory tract infections and improved bone health. Countries in the Northern hemisphere recommend universal infant vitamin D supplementation to optimise early vitamin D levels, despite the absence of large trials proving safety or efficacy for any disease outcome. With the aim of determining the clinical and cost-effectiveness of daily vitamin D supplementation in breastfed infants from age 6–8 weeks to 12 months of age, we have started a double-blind, randomised, placebo-controlled trial of daily 400 IU vitamin D supplementation during the first year of life, VITALITY. Methods nd analysis Infants (n=3012) who are fully breastfed and not receiving vitamin D supplementation will be recruited at the time of their first immunisation, from council-led immunisation clinics throughout metropolitan Melbourne, Australia. The primary outcome is challenge-proven food allergy at 12 months of age. Secondary outcomes are food sensitisation (positive skin prick test), number of lower respiratory infections (through hospital linkage), moderately-severe and persistent eczema (by history and examination) and vitamin D deficiency (serum vitamin D <50 nmol/L) at age 12 months. The trial is underway and the first 130 participants have been recruited

Updated threshold dose-distribution data for sesame

Sesame is classified as a “major” food allergen for which mandatory disclosure is required. Understanding reaction thresholds and how these vary within the allergic population is crucial in providing appropriate dietary advice to patients, providing guidance to the food industry, and informing dosing regimens for oral food challenges (FC). However, the largest data series used to derive a threshold dose-distribution for sesame included blinded challenge data from just 40 individuals.1 Data from low-dose, open FC can be used to supplement that from blinded FC, reducing uncertainty in estimating threshold dose-distributions for allergenic foods which otherwise lack sufficient data.2 We, therefore, undertook a systematic search of the literature and performed dose-distribution modelling of individual patient FC data (including open FC) to update estimated eliciting doses for sesame

The Exposome Approach in Allergies and Lung Diseases: Is It Time to Define a Preconception Exposome?

Emerging research suggests environmental exposures before conception may adversely affect allergies and lung diseases in future generations. Most studies are limited as they have focused on single exposures, not considering that these diseases have a multifactorial origin in which environmental and lifestyle factors are likely to interact. Traditional exposure assessment methods fail to capture the interactions among environmental exposures and their impact on fundamental biological processes, as well as individual and temporal factors. A valid estimation of exposure preconception is difficult since the human reproductive cycle spans decades and the access to germ cells is limited. The exposome is defined as the cumulative measure of external exposures on an organism (external exposome), and the associated biological responses (endogenous exposome) throughout the lifespan, from conception and onwards. An exposome approach implies a targeted or agnostic analysis of the concurrent and temporal multiple exposures, and may, together with recent technological advances, improve the assessment of the environmental contributors to health and disease. This review describes the current knowledge on preconception environmental exposures as related to respiratory health outcomes in offspring. We discuss the usefulness and feasibility of using an exposome approach in this research, advocating for the preconception exposure window to become included in the exposome concept

Father's environment before conception and asthma risk in his children: a multi-generation analysis of the Respiratory Health In Northern Europe study

Whereas it is generally accepted that maternal environment plays a key role in child health, emerging evidence suggests that paternal environment before conception also impacts child health. We aimed to investigate the association between children's asthma risk and parental smoking and welding exposures prior to conception.; In a longitudinal, multi-country study, parents of 24 168 offspring aged 2-51 years provided information on their life-course smoking habits, occupational exposure to welding and metal fumes, and offspring's asthma before/after age 10 years and hay fever. Logistic regressions investigated the relevant associations controlled for age, study centre, parental characteristics (age, asthma, education) and clustering by family.; Non-allergic early-onset asthma (asthma without hay fever, present in 5.8%) was more common in the offspring with fathers who smoked before conception {odds ratio [OR] = 1.68 [95% confidence interval (CI) = 1.18-2.41]}, whereas mothers' smoking before conception did not predict offspring asthma. The risk was highest if father started smoking before age 15 years [3.24 (1.67-6.27)], even if he stopped more than 5 years before conception [2.68 (1.17-6.13)]. Fathers' pre-conception welding was independently associated with non-allergic asthma in his offspring [1.80 (1.29-2.50)]. There was no effect if the father started welding or smoking after birth. The associations were consistent across countries.; Environmental exposures in young men appear to influence the respiratory health of their offspring born many years later. Influences during susceptible stages of spermatocyte development might be important and needs further investigation in humans. We hypothesize that protecting young men from harmful exposures may lead to improved respiratory health in future generations

The Impact of Family History of Allergy on Risk of Food Allergy: A Population-Based Study of Infants

The apparent rapid increase in IgE-mediated food allergy and its implications are now widely recognized, but little is known about the relationship between family history (an indirect measure of genetic risk) and the risk of food allergy. In a population-based study of 5,276 one year old infants (HealthNuts), the prevalence of oral food challenge-confirmed food allergy was measured. Associations between family history of allergic disease and food allergy in infants were examined using multiple logistic regression. Food allergy was diagnosed in 534 infants. Compared to those with no family history of allergic disease, children meeting the current definition of “high risk” for allergic disease (one immediate family member with a history of any allergic disease) showed only a modest increase (OR 1.4, 95% CI 1.1–1.7) in food allergy, while having two or more allergic family members was more strongly predictive of food allergy in the child (OR 1.8, 95% CI 1.5–2.3). There were also differences in the associations between family history and egg and peanut allergy in the child. Re-defining “high risk” as two or more allergic family members may be more useful for identification of groups with a significantly increased risk of food allergy both clinically and within research studies