The AusPollen partnership project: Allergenic airborne grass pollen seasonality and magnitude across temperate and subtropical eastern Australia, 2016-2020.

BACKGROUND: Allergic rhinitis affects half a billion people globally, including a fifth of the Australian population. As the foremost outdoor allergen source, ambient grass pollen exposure is likely to be altered by climate change. The AusPollen Partnership aimed to standardize pollen monitoring and examine broad-scale biogeographical and meteorological factors influencing interannual variation in seasonality of grass pollen aerobiology in Australia. METHODS: Daily airborne grass and other pollen concentrations in four eastern Australian cities separated by over 1700 km, were simultaneously monitored using Hirst-style samplers following the Australian Interim Pollen and Spore Monitoring Standard and Protocols over four seasons from 2016 to 2020. The grass seasonal pollen integral was determined. Gridded rainfall, temperature, and satellite-derived grassland sources up to 100 km from the monitoring site were analysed. RESULTS: The complexity of grass pollen seasons was related to latitude with multiple major summer-autumn peaks in Brisbane, major spring and minor summer peaks in Sydney and Canberra, and single major spring peaks occurring in Melbourne. The subtropical site of Brisbane showed a higher proportion of grass out of total pollen than more temperate sites. The magnitude of the grass seasonal pollen integral was correlated with pasture greenness, rainfall and number of days over 30 °C, preceding and within the season, up to 100 km radii from monitoring sites. CONCLUSIONS: Interannual fluctuations in Australian grass pollen season magnitude are strongly influenced by regional biogeography and both pre- and in-season weather. This first continental scale, Southern Hemisphere standardized aerobiology dataset forms the basis to track shifts in pollen seasonality, biodiversity and impacts on allergic respiratory diseases.

Global Climate Change and Pollen Aeroallergens: A Southern Hemisphere Perspective.

Climatic change will have an impact on production and release of pollen, with consequences for the duration and magnitude of aeroallergen seasonal exposure and allergic diseases. Evaluations of pollen aerobiology in the southern hemisphere have been limited by resourcing and the density of monitoring sites. This review emphasizes inconsistencies in pollen monitoring methods and metrics used globally. Research should consider unique southern hemisphere biodiversity, climate, plant distributions, standardization of pollen aerobiology, automation, and environmental integration. For both hemispheres, there is a clear need for better understanding of likely influences of climate change and comprehending their impact on pollen-related health outcomes.

Tree pollen exposure is associated with reduced lung function in children.

BACKGROUND: Allergic disease is a recognized global epidemic and a significant cause of ill health and poor quality of life. The prevalence of pollen allergy is high throughout the world, and pollen exposure itself plays a role in emergency department presentations and hospitalizations for asthma. Lung function and airway inflammation are important measures of asthma activity and control. OBJECTIVE: To examine associations between exposure to multiple pollen types and lung function and markers of airway inflammation at 8 and 14 years of age, and to explore potential modification by residential greenness. METHODS: A cohort of high-risk children living in Sydney, Australia had spirometry and fractional exhaled nitric oxide (FeNO) measured at 8 and 14 years of age. Ambient pollen concentration on the day of lung function measurement and up to three days prior was used as the exposure measure. Residential greenness was derived from satellite imagery. We modelled the association between six pollen types and lung function and FeNO. We also assessed modifying effects of residential greenness. RESULTS: Casuarina, cypress and Pinus pollen in the air the day before measurement and 3 days prior respectively, were associated with reduced lung function in 8-year-olds. The pollen exposures were associated with decreases in FEV1 and FVC; however, the FEV1 /FVC ratio was not affected. Effect modification by greenness was not observed due to loss of power. CONCLUSIONS & CLINICAL RELEVANCE: Airborne tree pollen of cypress, Casuarina and Pinus and not grass in some regions may be detrimental to childhood lung function.

Using crowd-sourced allergic rhinitis symptom data to improve grass pollen forecasts and predict individual symptoms.

Seasonal allergic rhinitis (AR), also known as hay fever, is a common respiratory condition brought on by a range of environmental triggers. Previous work has characterised the relationships between community-level AR symptoms collected using mobile apps in two Australian cities, Canberra and Melbourne, and various environmental covariates including pollen. Here, we build on these relationships by assessing the skill of models that provide a next-day forecast of an individual's risk of developing AR and that nowcast ambient grass pollen concentrations using crowd-sourced AR symptoms as a predictor. Categorical grass pollen forecasts (low/moderate/high) were made based on binning mean daily symptom scores by corresponding categories. Models for an individual's risk were constructed by forward variable selection, considering environmental, demographic, behaviour and health-related inputs, with non-linear responses permitted. Proportional-odds logistic regression was then applied with the variables selected, modelling the symptom scores on their original five-point scale. AR symptom-based estimates of today's average grass pollen concentration were more accurate than those provided by two benchmark forecasting methods using various metrics for assessing accuracy. Predictions of an individual's next-day AR symptoms rated on a five-point scale were correct in 36% of cases and within one point on this scale in 82% of cases. Both outcomes were significantly better than chance. This large-scale AR symptoms measurement program shows that crowd-sourced symptom scores can be used to predict the daily average grass pollen concentration, as well as provide a personalised AR forecast.

Crowd-sourced allergic rhinitis symptom data: The influence of environmental and demographic factors.

Allergic Rhinitis (AR) affects over half a billion people worldwide with an estimated prevalence of 1 in 5 individuals in developed countries. Although ambient pollen exposure is a causal factor in AR, the symptom-exposure relationship is typically not studied in the broader community but in small, well-characterised cohorts drawn from clinical populations. To identify relationships between AR symptoms in the community and a range of environmental factors, we used a database containing over 96,000 symptom score reports collected over a 3-year period (2014-2016) through freely available smartphone apps released in two Australian cities, Melbourne and Canberra. Ambient pollen levels and symptom scores were strongly related, with grass pollen explaining most of the symptom variation. Other factors correlated with higher symptom scores included temperature (R > 0.73) and wind speed (R > 0.75). In general, worse symptom scores were reported by younger participants, women, and those who had taken medication for AR in the preceding 24 h. The strength of this relationship varied between the two cities. Smartphone-based symptom surveys offer a cost-effective means of studying real-world risk factors for AR in a broader 'extra-clinical' population.

The use of biologic agents in the management of uveitis.

The uveitides are a heterogenous group of ocular inflammatory disorders that account for the third highest cause of blindness worldwide, responsible for 5-10% of visual impairment globally. Up to 35% of patients with uveitis can suffer significant vision loss. To prevent irreversible structural damage and blindness, it is important that the diagnosis and commencement of appropriate therapy occurs promptly. Management includes topical and systemic corticosteroid therapy and conventional immunomodulatory agents, including methotrexate, azathioprine, mycophenolate mofetil and cyclosporin. Significant progress has been made in the past decade in our understanding of the immunopathological pathways that drive intraocular inflammation, allowing the development of targeted therapy with biologic agents. These include TNF-α inhibitors, such as infliximab, adalimumab and etanercept; interleukin blockers, such as tocilizumab and daclizumab; and other targeted therapies, such as rituximab and abatacept. The efficacy of these agents has been studied in cases of severe uveitis that are refractory to conventional immunomodulatory agents and provide exciting results that have revolutionised uveitis management. Though the biologic era has provided a large armamentarium to treat uveitis, ongoing challenges and cases of recalcitrant uveitis remain, posing a challenge to internal medicine physicians. This comprehensive review aims to construct an updated summary on the existing evidence pertaining to the use of biologic agents in the treatment of uveitis. Methods include a systematic search for studies between 2000 and 2018 using PubMed, EMBASE, Ovid MEDLINE and Cochrane libraries.

High ambient levels of grass, weed and other pollen are associated with asthma admissions in children and adolescents: A large 5-year case-crossover study.

BACKGROUND: Pollen is an important aeroallergen that triggers asthma exacerbations in children, but we know little about the impact of different pollen types in cities with varying climatic conditions and pollen seasons. OBJECTIVES: We aimed to assess the role of ambient level of different types of pollen on a large time series of child and adolescent asthma hospitalizations in Sydney, Australia. METHODS: Childhood asthma hospitalization and the daily ambient pollen concentrations of different species were collected in South-West Sydney. With a bidirectional case-crossover design, we fitted conditional logistic regression models to measure the associations between instantaneous and up to 3 days lagged effects of pollen concentrations on asthma hospitalizations after controlling for potential confounders and testing for interactions. RESULTS: A total of 2098 children, more boys (59.7%) and 2-5 years old (62.6%), were hospitalized due to asthma. The geometric mean concentration of Cupressus, 7.88 [5.02] grains/m3 , was the highest during the study period. The increase from 75th to 90th percentile of grass (OR = 1.037, 95% CI 1.005-1.070), weed other than Plantago species (OR = 1.053, 95% CI 1.009-1.098) and unclassified pollen (OR = 1.034, 95% CI 1.010-1.058) were significantly associated with the odds of asthma hospitalizations. Boys were at greater risk of asthma exacerbations associated with grass (OR = 1.046, 95% CI 1.003-1.090) and unclassified pollen (OR = 1.041, 95% CI 1.010-1.073). There was evidence of effect modification by age groups for Cupressus, conifer, total tree and total pollen. CONCLUSIONS: Although boys are more vulnerable to grass pollen, weed, and other pollen are also important triggers of asthma exacerbations in all children and adolescents. These findings are important for urban green space planning and the development of pollen monitoring systems for families with children at risk of asthma exacerbations during peak pollen seasons.

Climate change: allergens and allergic diseases.

Climate change has been described as the biggest global health threat of the 21st century. The atmospheric concentrations of greenhouse gases, such as carbon dioxide, methane and nitrous oxide, have increased significantly since the start of the Industrial Era around 1750, with much of this increase occurring over just the last 50 years or so. This is resulting in warming of the climate system as well as changes in precipitation and weather and climate extremes. These changes in climate are having wide-ranging impacts on the Earth's physical, biological and human systems, including human health. It is these impacts of climate change on human health that are the focus of this paper, particularly the impacts on allergens and allergic diseases. Such impacts are particularly significant in many countries where the prevalence of such diseases is high and/or increasing. There is now compelling evidence that rising air temperatures and carbon dioxide concentrations are, in some plant species, resulting in increased pollen production and allergenicity and advancement and lengthening of the pollen season. Changes in extreme events, such as thunderstorms and tropical cyclones, will also have impacts on allergic diseases, with, for example, the flooding associated with tropical cyclones leading to proliferation of mould growth in damp homes. The article also considers a range of responses to these health threats, including greenhouse gas mitigation, and adaptation strategies, such as enhanced environmental monitoring and health surveillance and adequate planning for the future medical workforce.

The role of outdoor fungi on asthma hospital admissions in children and adolescents: A 5-year time stratified case-crossover analysis.

BACKGROUND: Some fungal spores can trigger asthma exacerbation but knowledge of which outdoor fungal spores contribute to asthma hospitalisation is limited. OBJECTIVES: To examine the role of outdoor fungal spores in child and adolescent asthma hospitalisations. METHODS: We conducted a bi-directional time-stratified case-crossover study of child and adolescent asthma hospitalisations over 5 years. Conditional logistic regression assessed the role of 20 fungi taxa (Same day [L0] and lagged [L1-3]) adjusted for maximum temperature, humidity and grass pollen. Strata specific effects were explored if there was evidence of effect modification by age, sex, air pollutants or grass pollen. Non-linear effects examined with Generalized Additive Models. RESULTS: Of 2098 children hospitalised for asthma, 60% were boys; mean age was 5.5±3.7 years. Fungal spore counts peaked during warm months. Regression models found weak associations with Coprinus [L0,L1: OR=1.03, 1.01-1.06], Periconia [L0: OR=1.03, 1.001-1.07] and Chaetomium [L2: OR=1.08, 1.0-1.2]. Sex appeared to act as an effect modifier with girls having stronger associations with Cladosporium, Coprinus and total fungi. Older adolescent (14-18 years) hospitalisation was significantly associated with Coprinus and Ustilago/smuts. Air pollutants and grass pollen did not appear to act as effect modifiers. Non-linearity was not detected. CONCLUSION: There may be associations between some outdoor fungal spores and asthma hospitalisations. Further research needed to explore whether these findings can be replicated; and examine whether fungal sensitisation and/or human rhinovirus infections are associated with stronger effects. If findings are replicated, then the need to develop predictive models for fungal spore distribution and levels may become more important.

Should patients with pollen fruit syndrome be prescribed an automatic epinephrine injector?

PURPOSE OF REVIEW: The review outlines recent insights into our understanding of the complex relationships between pollen and plant food sensitization patterns resulting in the pollen fruit syndrome and the possible risk, upon ingestion, of generalized symptoms rather than localized oropharyngeal reactions. Appreciation of this risk will inform management strategies, which include epinephrine prescription. RECENT FINDINGS: In recent times, the ability to examine molecular components of foods and pollen has allowed further delineation of reactivity patterns. These reveal complex patterns of IgE reactivity and sensitization pathways. More precise definition of these patterns will allow a more accurate analysis of risk of severe food reactions following ingestion. SUMMARY: Despite improvement in diagnostic tests, there remains no completely reliable way to determine whether an individual with pollen fruit syndrome is at risk of a systemic reaction. The decision to prescribe an epinephrine autoinjector must be based on a risk assessment for the individual patient.

Differences in grass pollen allergen exposure across Australia.

OBJECTIVE: Allergic rhinitis and allergic asthma are important chronic diseases posing serious public health issues in Australia with associated medical, economic, and societal burdens. Pollen are significant sources of clinically relevant outdoor aeroallergens, recognised as both a major trigger for, and cause of, allergic respiratory diseases. This study aimed to provide a national, and indeed international, perspective on the state of Australian pollen data using a large representative sample. METHODS: Atmospheric grass pollen concentration is examined over a number of years within the period 1995 to 2013 for Brisbane, Canberra, Darwin, Hobart, Melbourne, and Sydney, including determination of the 'clinical' grass pollen season and grass pollen peak. RESULTS: The results of this study describe, for the first time, a striking spatial and temporal variability in grass pollen seasons in Australia, with important implications for clinicians and public health professionals, and the Australian grass pollen-allergic community. CONCLUSIONS: These results demonstrate that static pollen calendars are of limited utility and in some cases misleading. This study also highlights significant deficiencies and limitations in the existing Australian pollen monitoring and data. IMPLICATIONS: Establishment of an Australian national pollen monitoring network would help facilitate advances in the clinical and public health management of the millions of Australians with asthma and allergic rhinitis.

The prevalence of the oral allergy syndrome and pollen-food syndrome in an atopic paediatric population in south-west Sydney.

AIM: Oral allergy syndrome (OAS) and pollen-food syndrome (PFS) are regarded as uncommon manifestations of paediatric atopic disease. However, little Australian data exist. The aim of this study was to examine the prevalence of OAS in an atopic, paediatric population. METHODS: This cross-sectional study assessed 163 patients aged 4-17 years from the Paediatric Allergy & Immunology Clinic at Campbelltown Hospital, which serves a population base >250,000 with approximately 28% under the age of 18 years. A questionnaire was administered and skin prick tests (SPTs) were performed utilising commercial extracts and fresh and frozen fruit samples. Frozen samples were created by reducing fresh fruit to a semi-solid state and storing at -20 degrees Celsius for up to 6 months. RESULTS: Within the studied population, the prevalence of OAS was 14.7%, PFS 4.9%, PFS in those with allergic rhinitis 6.25% and PFS in those with allergic rhinitis and pollen sensitisation 12.1%. All PFS-implicated fruits were tropical fruits with watermelon the most common. The prevalence of OAS caused by food allergy was 13.6%, implicating peanut most frequently. The most common cause of OAS was immunoglobulin E-mediated food allergy (57.9%). Only frozen samples of watermelon, pineapple and rockmelon produced results consistent with the 'gold standard' of fresh fruit SPT. CONCLUSION: This study suggests the prevalence of OAS and PFS are more common in paediatric populations than previously described, with tropical fruits predominantly implicated in PFS. Further research is required to determine whether frozen fruits are a reliable alternative to fresh fruit in SPT.

London Plane Tree bioaerosol exposure and allergic sensitization in Sydney, Australia.

BACKGROUND: Exposure to London Plane Tree (Platanus) bioaerosols in Sydney, Australia has been anecdotally linked to respiratory irritation, rhinitis, and conjunctivitis. OBJECTIVE: To determine the relationships between Platanus bioaerosol exposure, allergic sensitization, and symptoms. METHODS: Sixty-four subjects with self-reported Platanus symptoms were recruited from inner-urban Sydney. Allergic sensitization was determined by skin prick test (SPT) to 13 allergens. Airborne concentrations of Platanus pollen, trichomes, and achene fibers, and other pollen and fungal spores, were measured over the spring and summer of 2006-2007. Subjects' allergic symptoms were monitored concurrently. The Halogen immunoassay (HIA) was used to measure subjects' immunoglobulin E (IgE) reactivity to collected bioaerosols. RESULTS: Platanus pollen constituted 76% of total pollen between July 2006 and April 2007. Airborne concentrations of Platanus pollen peaked from August until October. Non-Platanus pollen peaked from July to December. Elevated concentrations of trichomes and achene fibers occurred from September to December and August to October, respectively. As determined by SPT, 85.9% of subjects were sensitized, 65.6% to any pollen tested, 56.3% to Lolium perenne, and 23.4% to Platanus. Higher mean daily symptom scores were only associated with high counts of non-Platanus pollens. HIA analysis demonstrated IgE binding to Platanus pollen in all Platanus sensitized subjects. Personal nasal air sampling detected airborne trichomes that were capable of being inhaled. Platanus trichomes or achene fibers did not bind IgE from any subject. CONCLUSIONS: Platanus bioaerosols exist in high concentrations between August and November in inner-urban Sydney but were not associated with seasonal symptoms. Platanus trichomes are inhaled and may constitute a respiratory irritant. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCTXXXXX.

Spatial variability in the pollen count in Sydney, Australia: can one sampling site accurately reflect the pollen count for a region?

BACKGROUND: There is increasing interest in the daily pollen count, with pollen-sensitive individuals using it to determine medication use and researchers relying on it for commencing clinical drug trials and assessing drug efficacy according to allergen exposure. Counts are often expressed qualitatively as low, medium, and high, and often only 1 pollen trap is used for an entire region. OBJECTIVES: To examine the spatial variability in the pollen count in Sydney, Australia, and to compare discrepancies among low-, medium-, and high-count days at 3 sites separated by a maximum of 30 km. METHODS: Three sites in western Sydney were sampled using Burkard traps. Data from the 3 sites were used to compare vegetation differences, possible effects of some meteorological parameters, and discrepancies among sites in low-, medium-, and high-count days. RESULTS: Total pollen counts during the spring months were 14,382 grains/m3 at Homebush, 11,584 grains/m3 at Eastern Creek, and 9,269 grains/m3 at Nepean. The only significant correlation between differences in meteorological parameters and differences in pollen counts was the Homebush-Nepean differences in rainfall and pollen counts. Comparison between low- and high-count days among the 3 sites revealed a discordance rate of 8% to 17%. CONCLUSIONS: For informing the public about pollen counts, the count from 1 trap is a reasonable estimation in a 30-km region; however, the discrepancies among 3 trap sites would have a significant impact on the performance of a clinical trial where enrollment was determined by a low or high count. Therefore, for clinical studies, data collection must be local and applicable to the study population.

Effects of intranasal budesonide on symptoms, quality of life, and performance in elite athletes with allergic rhinoconjunctivitis.

OBJECTIVE: To assess change in symptoms, quality of life (QOL), and performance ability before, during, and after treatment with budesonide in a group of Olympic and Paralympic athletes with seasonal allergic rhinoconjunctivitis (SAR/C). DESIGN: Because budesonide has already been proven to be an effective and well-tolerated treatment of SAR/C(1), an open-label treatment format was used. SETTING: The study was community-based with participating athletes preparing for Olympic competition. PARTICIPANTS: Olympic and Paralympic athletes were screened for the presence of SAR/C using history and positive skin test results for pollen allergens. INTERVENTIONS: All were offered treatment with intranasal budesonide, applied to each nostril, once daily for eight weeks. OUTCOME MEASUREMENTS: Symptom and medication diaries were completed before treatment and after 4 and 8 weeks of treatment. Similarly, Quality of Life (QOL) was measured with the Rhinoconjunctivitis Quality of Life Questionnaire. As a secondary outcome measure, the ability to train and compete was assessed using a performance diary. RESULTS: Of the 236 athletes eligible for the study, 145 (61%) agreed to participate. Forty-six percent of the athletes who were dispensed treatment did not return questionnaires. For those returning questionnaires, scores between baseline (week 0) and weeks 4 and 8 were calculated for total symptoms, QOL, and performance scores. There were statistically significant improvements in symptoms, QOL, and performance scores in athletes who used intranasal budesonide. CONCLUSION: SAR/C is a common condition and has demonstrable negative effects on athletes. Better education of coaches and athletes is necessary to ensure that the condition is correctly diagnosed and treated, with safe, effective, permitted medication.