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Objectives: Epidemic Thunderstorm asthma (TA) is a serious public health threat with a potential to overwhelm health systems. Being the first documented incidence in Ghana, we sought to determine whether the chronic respiratory risk factors for the development of TA as identified in other countries were similar or different from that in Ghana. Study design: A matched case-control study involving 41 cases and 82 controls was conducted in two conveniently selected health facilities in the Ashanti Region of Ghana. Methods: Data were collected from pre-existing patient records and included general demography, a history of allergies and a history of asthma. A chi-square and multiple logistic regression analysis were conducted to identify risk factors for the development of TA. Results: Overall, 53.7 % of the TA cases and 7.3 % of controls had a previous history of asthma (AOR = 4.53 p = 0.064, 95 % CI = 0.918–22.365). Also, 29.3 % of the cases and 1.2 % of the controls had a previous history of allergies (AOR = 12.48 p = 0.05, 95 % CI = 0.919–169.305). Conclusions: A previous history of allergy was a significant risk factor for TA. A previous history of asthma though associated with TA, was not a significant risk factor for its development. The recognition and awareness of risk factors for TA, by clinicians and health managers, is essential for health education, case management and preparation for the surge capacity occasioned by the event.

Severe asthma has been shown to occur in the combined presence of high pollen and thunderstorm conditions, also known as ‘thunderstorm asthma.’ First studied as severe epidemic events, recent longitudinal work studied less dramatic but more frequent occurrences. We explore thunderstorm asthma-related emergency department visits in the Minneapolis-St. Paul metropolitan area and evaluated risk differences by sex and age. We define a thunderstorm asthma exposure event as the daily occurrence of 2 or more lightning strikes during high pollen periods, and use daily counts of asthma-related emergency department visits to estimate relative and absolute risk of severe asthma during thunderstorm asthma events for the full population and for sex and age subgroups. The overall population had a 1.06 (95 % CI: 1.02, 1.09) times higher risk of asthma-related ED visits during thunderstorm asthma events compared to days without thunderstorm asthma events. Children under 18 show no higher risk (RR 1.02; 95 % CI: 0.97 1.08), but adults 18–44 years (RR 1.08; 95 % CI: 1.02, 1.13) and 45 and up (RR 1.08; 95 % CI 1.02, 1.15) show higher relative risk. Absolute risk measures show similar patterns to the age and sex results, but age-sex subgroups show more variation in absolute vs relative risk. Our results support an association between ED visits and thunderstorm asthma and provide evidence of varying risks by sex across the life course. These differences in risk have implications for clinical treatment of this allergic type of asthma and for future research into this poorly recognized environmental exposure.Plain Language Summary: Recent research has highlighted the existence of Thunderstorm asthma events, a phenomenon in which pollen grains rupture in the conditions that occur with a thunderstorm, releasing sub-pollen particles that are capable of triggering severe asthma in susceptible populations. Where severe asthma is a disease that usually impacts children, we find in this study that asthma ED visits associated with thunderstorm asthma events more frequently impact adults, particularly males 18–44 and females 45 and up.

Environmental changes, especially those observed in recent decades, have a tremendous effect on human health. There is a dramatic increase in the prevalence of allergies around the world at present. This trend is especially noticeable in developed countries and big cities. Currently, great attention is paid to studying the influence of changing environmental factors on the development and prevalence of allergic pathology. Global warming, air pollution, and extreme weather events are all contributes to the rise in allergies. [ABSTRACT FROM AUTHOR]

Background: There have been 26 epidemic thunderstorm asthma (ETSA) events worldwide, with Melbourne at the epicentre of ETSA with 7 recorded events, and in 2016 experienced the deadliest ETSA event ever recorded. Health services and emergency departments were overwhelmed with thousands requiring medical care for acute asthma and 10 people died. Objectives: This multidisciplinary study was conducted across various health and science departments with the aim of improving our collective understanding of the mechanism behind ETSA. Design: This study involved time-resolved analysis of atmospheric sampling of the air for pollen and fungal spores, and intact and ruptured pollen compared with different weather parameters, pollution levels and clinical asthma presentations. Methods: Time-resolved pollen and fungal spore data collected by Deakin Air WATCH Burwood, underwent 3-h analysis, to better reflect the 'before', 'during' and 'after' ETSA time points, on the days leading up to and following the Melbourne 2016 event. Linear correlations were conducted with atmospheric pollution data provided by the Environment Protection Authority (EPA) of Victoria, weather data sourced from Bureau of Meteorology (BOM) and clinical asthma presentation data from the Victorian Agency for Health Information (VAHI) of Department of Health. Results: Counts of ruptured grass pollen grains increased 250% when the thunderstorm outflow reached Burwood. Increased PM10, high relative humidity, decreased temperature and low ozone concentrations observed in the storm outflow were correlated with increased levels of ruptured grass pollen. In particular, high ozone levels observed 6 h prior to this ETSA event may be a critical early indicator of impending ETSA event, since high ozone levels have been linked to increasing pollen allergen content and reducing pollen integrity, which may in turn contribute to enhanced pollen rupture. Conclusion: The findings presented in this article highlight the importance of including ruptured pollen and time-resolved analysis to forecast ETSA events and thus save lives. [ABSTRACT FROM AUTHOR]

In recent years, the environmental impacts of climate change have become increasingly evident. Extreme meteorological events are influenced by climate change, which also alter the magnitude and pattern of precipitations and winds. Climate change can have a particularly negative impact on respiratory health, which can lead to the emergence of asthma and allergic respiratory illnesses. Pollen is one of the main components of the atmospheric bioaerosol and is able to induce allergic symptoms in certain subjects. Climate change affects the onset, length, and severity of the pollen season, with effects on pollen allergy. Higher levels of carbon dioxide (CO2) can lead to enhanced photosynthesis and a higher pollen production in plants. Pollen grains can also interact with air pollutants and be affected by thunderstorms and other extreme events, exacerbating the insurgence of respiratory diseases such as allergic rhinitis and asthma. The consequences of climate change might also favor the spreading of pandemics, such as the COVID-19 one. [ABSTRACT FROM AUTHOR]

Climate change is a key environmental factor for allergic respiratory diseases, especially in childhood. This review describes the influences of climate change on childhood asthma considering the factors acting directly, indirectly and with their amplifying interactions. Recent findings on the direct effects of temperature and weather changes, as well as the influences of climate change on air pollution, allergens, biocontaminants and their interplays, are discussed herein. The review also focusses on the impact of climate change on biodiversity loss and on migration status as a model to study environmental effects on childhood asthma onset and progression. Adaptation and mitigation strategies are urgently needed to prevent further respiratory diseases and human health damage in general, especially in younger and future generations. [ABSTRACT FROM AUTHOR]

Respiratory allergy has a strict correlation with air pollution and climate change increasing the presence in atmosphere of trigger factors such as pollens and molds able to induce rhinitis and asthma in sensitized patients with IgE-mediated allergic reactions. Pollen allergy is frequently used to evaluate the interrelation between air pollution and allergic respiratory diseases. Pollen allergens have been shown to trigger the release of immunomodulatory and pro-inflammatory mediators that accelerate the onset of respiratory allergy in children and adults. Lightning storms during pollen seasons can cause exacerbation of respiratory allergy and asthma in adults but also in children with pollinosis. Environmental pollution and climate change have harmful effects on human health, particularly on respiratory system, with frequent repercussions also on social systems. Climate change is characterized by physic meteorological events inducing increase of production and emission in atmosphere of anthropogenic carbon dioxide (CO2). Studies show that allergenic plants produce more pollen as a response to high atmospheric levels of carbon dioxide (CO2). Climate change affects also extreme atmospheric events such as heat waves, droughts, thunderstorms, floods, cyclones and hurricanes, increasing the intensity of asthma attacks in pollinosis patients during these events. Climate change has important effects on the start and pathogenetic aspects of hypersensitivity of pollen allergy. Climate change causes an increase in the production of pollen and a change in the aspects increasing their allergenic properties. Through the effects of climate change plant growth can be altered so that the new pollen produced are modified affecting more the human health. The need for public education and adoption of governmental measures to prevent environmental pollution and climate change are urgent. Efforts to reduce greenhouse gases, chemical and biologic contributors to air pollution are of critical importance. Extreme weather phenomena such as thunderstorms can trigger exacerbations of asthma attacks and need to be prevented with a correct information and therapy. [ABSTRACT FROM AUTHOR]

Pollen, one type of primary biological aerosol particle (PBAP), is emitted from the terrestrial biosphere and can undergo physical changes in the atmosphere via particle rupture. To examine the fate of pollen and its atmospheric processing, a pollen emission and transport scheme is coupled to the Weather Research and Forecasting Model with Chemistry (WRF‐Chem). We simulate the emission of pollen and its impacts on the cloud properties and precipitation in the Southern Great Plains from 12 to 19 April 2013, a period with both high pollen emissions and convective activity. We conduct a suite of ensemble runs that simulate primary pollen and three different pollen rupture mechanisms that generate subpollen particles, including (a) high humidity‐induced surface rupture, (b) high humidity‐induced in‐atmosphere plus surface rupture, and (c) lightning‐induced rupture, where in‐cloud and cloud‐to‐ground lightning strikes trigger pollen rupture events. When relative humidity is high (>80%), coarse primary pollen (∼1 μg m−3) is converted into fine subpollen particles (∼1.2e−4 μg m−3), which produces 80% more subpollen particles than lightning‐induced rupture. The in‐atmosphere humidity‐driven rupture predominantly produces subpollen particles, which is further enhanced during a frontal thunderstorm. During strong convection, vertical updrafts lift primary pollen and subpollen particles (∼0.5e−4 μg m−3) to the upper troposphere (∼12 km) and laterally transports the ruptured pollen in the anvil top outflow. In regions of high pollen and strong convection, ruptured pollen can influence warm cloud formation by decreasing low cloud (<4 km) cloud water mixing ratios and increasing ice phase hydrometeors aloft (>10 km). Plain Language Summary: Biological aerosols like pollen are released from the terrestrial biosphere into the atmosphere and affect atmospheric processes, hydrology, and climate. For example, large primary pollen ruptures in different atmospheric conditions to produce multiple small‐sized pollen fragments. Moreover, these ruptured particles can trigger thunderstorm asthma. In this study, a Weather Research and Forecasting Model with Chemistry was used to evaluate the fate of pollen in the atmosphere. Model simulations indicate that the three pollen rupture mechanisms, including high humidity‐induced surface rupture, in‐atmosphere plus surface rupture, and lightning‐induced rupture, influence the overall pollen load over the Southern Great Plains during convective days with high pollen emissions. The SPP are produced in the highest concentrations in the atmosphere and on the surface due to the high relative humidity‐induced‐rupture. Even though in‐cloud and cloud‐to‐ground lightning strikes trigger pollen rupture events, they cannot produce as much as humidity‐induced ruptures. The ruptured pollen is transported to higher altitudes by vertical updrafts, horizontally through the outflows from the top of the clouds, and finally to the surface by the downdraft. In regions of high pollen and strong convection, ruptured particles can further alter the hydrometeors and influence cloud formation. Key Points: The greatest amount of subpollen particles is formed from surface and in‐atmosphere humidity‐driven primary pollen ruptureVertical updrafts lift pollen to the upper troposphere (∼12 km) during convective eventsRuptured pollen can reduce cloud water mixing ratios and slightly increase ice phase hydrometeors aloft [ABSTRACT FROM AUTHOR]

Higher incidences of asthma during thunderstorms can pose a serious health risk. In this study, we estimate the thunderstorm asthma risk using statistical methods, with special focus on Bavaria, Southern Germany. In this approach, a dataset of asthma-related emergency cases for the study region is combined with meteorological variables and aeroallergen data to identify statistical relationships between the occurrence of asthma (predictand) and different environmental parameters (set of predictors). On the one hand, the results provide evidence for a weak but significant relationship between atmospheric stability indices and asthma emergencies in the region, but also show that currently thunderstorm asthma is not a major concern in Bavaria due to overall low incidences. As thunderstorm asthma can have severe consequences for allergic patients, the presented approach can be important for the development of emergency strategies in regions affected by thunderstorm asthma and under present and future climate change conditions. [ABSTRACT FROM AUTHOR]

Josh Chatelier,1,2 Samantha Chan,1– 3 Ju Ann Tan,1,2 Alastair G Stewart,4,5 Jo Anne Douglass1,2 1Department of Clinical Immunology and Allergy, Royal Melbourne Hospital, Parkville, Victoria, Australia; 2Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia; 3Immunology Division, The Walter & Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia; 4Department of Biochemistry and Pharmacology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia; 5ARC Centre for Personalised Therapeutics Technologies, University of Melbourne, Melbourne, Victoria, AustraliaCorrespondence: Josh ChatelierDepartment of Clinical Immunology and Allergy, Royal Melbourne Hospital, Parkville, Victoria, AustraliaTel +61 3 9342 7191Fax + 61 3 9349 3199Email josh.chatelier2@mh.org.auAbstract: Epidemic thunderstorm asthma (ETSA) occurs following a thunderstorm due to the interaction of environmental and immunologic factors. Whilst first reported in the 1980s, the world’s largest event in Melbourne, Australia, on November 21, 2016 has led to a wealth of clinical literature seeking to identify its mechanisms, susceptibility risk factors, and management approaches. Thunderstorm asthma (TA) typically presents during an aeroallergen season in individuals sensitized to perennial rye grass pollen (RGP) in Australia, or fungus in the United Kingdom, in combination with meteorological factors such as thunderstorms and lightning activity. It is now well recognized that large pollen grains, which usually lodge in the upper airway causing seasonal allergic rhinitis (SAR), are ruptured during these events, leading to sub-pollen particles respirable to the lower respiratory tract causing acute asthma. The identified risk factors of aeroallergen sensitization, specifically to RGP in Australians with a history of SAR, and individuals born in Australia of South-East Asian descent as a risk factor for TA has been key in selecting appropriate patients for preventative management. Moreover, severity-determining risk factors for ETSA-related asthma admission or mortality, including pre-existing asthma or prior hospitalization, poor inhaled corticosteroid adherence, and outdoor location at the time of the storm are important in identifying those who may require more aggressive treatment approaches. Basic treatments include optimizing asthma control and adherence to inhaled corticosteroid therapy, treatment of SAR, and education regarding TA to increase recognition of at-risk days. Precision treatment approaches may be more beneficial in select individuals, including the use of allergen immunotherapy and even biologic treatment to mitigate asthma severity. Finally, we discuss the importance of environmental health literacy in the context of concerns surrounding the increased frequency of ETSA due to climate change and its implications for the frequency and severity of future events.Keywords: epidemic thunderstorm asthma, thunderstorm asthma, seasonal allergic rhinitis

In recent years, the environmental impacts of climate change have become increasingly evident. Extreme meteorological events are influenced by climate change, which also alter the magnitude and pattern of precipitations and winds. Climate change can have a particularly negative impact on respiratory health, which can lead to the emergence of asthma and allergic respiratory illnesses. Pollen is one of the main components of the atmospheric bioaerosol and is able to induce allergic symptoms in certain subjects. Climate change affects the onset, length, and severity of the pollen season, with effects on pollen allergy. Higher levels of carbon dioxide (CO2) can lead to enhanced photosynthesis and a higher pollen production in plants. Pollen grains can also interact with air pollutants and be affected by thunderstorms and other extreme events, exacerbating the insurgence of respiratory diseases such as allergic rhinitis and asthma. The consequences of climate change might also favor the spreading of pandemics, such as the COVID-19 one.

Grass pollens have been identified as mediators of respiratory distress, capable of exacerbating respiratory diseases including epidemic thunderstorm asthma (ETSA). It is hypothesised that during thunderstorms, grass pollen grains swell to absorb atmospheric water, rupture, and release internal protein content to the atmosphere. The inhalation of atmospheric grass pollen proteins results in deadly ETSA events. We sought to identify the underlying cellular mechanisms that may contribute towards the severity of ETSA in temperate climates using Timothy grass (Phleum pratense). Respiratory cells exposed to Timothy grass pollen protein extract (PPE) caused cells to undergo hypoxia ultimately triggering the subcellular re-organisation of F-actin from the peri junctional belt to cytoplasmic fibre assembly traversing the cell body. This change in actin configuration coincided with the spatial reorganisation of microtubules and importantly, decreased cell compressibility specifically at the cell centre. Further to this, we find that the pollen-induced reorganisation of the actin cytoskeleton prompting secretion of the pro-inflammatory cytokine, interleukin-8. In addition, the loss of peri-junctional actin following exposure to pollen proteins was accompanied by the release of epithelial transmembrane protein, E-cadherin from cell–cell junctions resulting in a decrease in epithelial barrier integrity. We demonstrate that Timothy grass pollen regulates F-actin dynamics and E-cadherin localisation in respiratory cells to mediate cell–cell junctional integrity highlighting a possible molecular pathway underpinning ETSA events. [ABSTRACT FROM AUTHOR]

Despite making up a significant proportion of airborne allergens, the relationship between fungal spores and asthma is not fully explored. Only 80 taxa of fungi have so far been observed to exacerbate respiratory presentations, with Cladosporium spp., Aspergillus spp., Penicillium spp., and Alternaria spp. found to comprise the predominant allergenic airborne spores. Fungal spores have been found in indoor environments, such as hospitals and housing due to poor ventilation. Meanwhile, outdoor fungal spores exhibit greater diversity, and higher abundance and have been associated with hospitalizations from acute asthma presentations. In addition, fungal spores may be the underlying, and perhaps the "missing link", factor influencing the heightened rate of asthma presentations during epidemic thunderstorm asthma events. To improve our knowledge gap on fungal spores, airborne allergen monitoring must be improved to include not only dominant allergenic fungi but also provide real-time data to accurately and quickly warn the general public. Such data will help prevent future asthma exacerbations and thus save lives. In this review, we examine the health risks of prominent allergenic fungal taxa, the factors influencing spore dispersal and distribution, and why improvements should be made to current sampling methods for public health and wellbeing. [ABSTRACT FROM AUTHOR]

Background and objective On 21 November 2016, parts of Victoria experienced a devastating epidemic thunderstorm asthma (ETSA) event. The aim of this study was to describe the epidemiology and burden of the 2016 ETSA event at MedicineInsight-registered general practices in the Melbourne metropolitan area in Victoria, Australia. Methods A cross-sectional study was conducted using patient record data from 21–23 November 2016. Codes were developed to identify all patients presenting to MedicineInsight-registered general practices with asthma during the 2016 ETSA event. Results During the event, there were 787 more asthma-related encounters to MedicineInsight general practices than expected, which represented a 7.1-fold increase (605% increase). Estimates suggest that there were between approximately 8940 and 13,689 more asthma-related encounters than expected across metropolitan Melbourne. Discussion General practices were significantly affected by the 2016 ETSA event. This work highlights the important part that general practices play in responding to ETSA events and the need for these practices to be prepared to respond. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reports of thunderstorm asthma in the Middle East are few. This study is the first to report on cases of near-fatal and fatal thunderstorm asthma in Kuwait on December 1, 2016. METHODS: We conducted a chart review and interview with adult patients admitted to Mubarak Al-Kabir Hospital with near-fatal asthma, defined as an exacerbation requiring intubation and mechanical ventilation or hypercapnia with a PaCO2≥6 kPa. Information, including patient age, gender, occupation, asthma history, medication usage, and clinical outcome, was collected. For fatal asthma cases, patients' data were collected from the Forensic Department at the Kuwait Ministry of Interior. RESULTS: A total of 17 patients were admitted with near-fatal asthma. Fifteen patients (93.8%) had a prior history of asthma, with an average duration of 9 years. Five patients (33.3%) reported receiving a corticosteroid inhaler from their physician. Fifteen patients (93.8%) reported relying on a short-acting β2-agonist alone to manage their asthma. Eleven patients (68.8%) reported being outdoors during the storm. Eleven patients were diagnosed with fatal asthma. CONCLUSION: The study is the first to report on a thunderstorm-associated asthma epidemic in Kuwait and emphasizes the potential dangers associated with this entity.

Raindrops brim with pollen even when there is no ambient local pollen. How does this nonlocal pollen get inside rain? The likely answer is long-range transport beneath or inside clouds. To test this hypothesis, we captured rain-delivered pollen on Ocracoke Island, NC, USA over a 12-day interval before local pine pollen release then reconstructed its trajectory and its atmospheric exposure conditions. Findings were as follows: four rain episodes yielded a total of 632 pollen grains of which 6.7% germinated. To find pollen sources, we first identified pollen-releasing forested areas using a predictive heat sum equation for each rain episode. Next, we constructed the backward trajectory for air parcels carrying rain-delivered pollen from those forests using the MLDP atmospheric transport and dispersion model. Nonlocal sources were located at distances up to 300 km from Ocracoke Island and distances lessened with each successive episode. Below-cloud transport time was 8 and 17 h for Episodes A and B, respectively. Pollen grains were exposed to harsh atmospheric conditions during below-cloud transport, yet some grains still germinated. Atmospheric turbulence patterns changed for each episode, so distance from pollen source was poorly correlated with pollen transport time. Pollen germination was not closely correlated with either distances or transport time. In-cloud transport was more likely for pollen sampled during Episodes C and D. Pine pollen, although rarely allergenic, brings fresh insights into how atmospheric events can trigger human respiratory distress. [ABSTRACT FROM AUTHOR]

To understand the challenges faced by general practice (GP) services in terms of personnel, materials, secondary support services, and discharge and communication obstacles during the thunderstorm asthma (TA) epidemic in 2016. Qualitative study using semi-structured interviews and focus groups between September and October 2017. Participants were general practitioners (GPs), practice nurses, and administrative staff working on the TA epidemic days in the northern region of Melbourne, Australia. 18 participants contributed to the study from six clinic sites. Both daytime and evening clinics experienced a surge in respiratory patient presentations. After-hours clinics were inundated with asthma patients during the night of the thunderstorm. Consistent themes emerged about the challenges encountered by participants the most significant being limitation of medication, equipment, space, and personnel. The extraordinary influx of patients necessitated participants innovate solutions including recycling equipment, procuring medications from hospitals and community pharmacies, triage, altering management strategies and extending clinic hours. Participants were limited by the paucity of information from local services during the TA epidemic. This study supports the view that GP services made a substantial contribution to the emergency response on the evening of the TA epidemic that occurred in Melbourne in 2016. Demands on resources were considerable during and after the epidemic yet GP staff showed great resilience increasing clinic surge capacity. Our findings indicate significant barriers at an organizational level including resource limitations, inadequate operational information, and the absence of timely communication channels that impaired the response of GP services during a TA event. [ABSTRACT FROM AUTHOR]

Background: The so‐called "thunderstorm asthma" (TA) is an uncommon but dramatic outbreak of asthma attacks occurring during a thunderstorm in the pollen and moulds season. Mechanisms which make the pollen able to enter the deeper airways and provoke severe asthma symptoms are still unclear. Objective: To test the hypothesis that sub‐pollen particles (SPPs) originated from the rupture by an osmotic shock of pollen associated with TA contain allergens. Methods: After hydration, SPPs released from pollen grains of grass, pellitory, olive, cypress, ragweed and birch were isolated and determined by microscopy. Allergens were determined by in vitro ELISA inhibition tests indirectly using the sera from 10 polyreactive patients. An inhibition <50% was considered as negative, 50%‐75% moderate and > 75% complete. Results: The inhibition experiments showed that the SPPs from birch and cypress were unable to inhibit serum IgE reactivity to Bet v 1 and Cup a 1, respectively. Ragweed SPPs inhibited ragweed pollen extract and Amb a 1 by 75.8 ± 0.11% and 81.2 ± 0.15%, respectively. Olive and pellitory SPPs retained almost the whole IgE‐binding capability in all cases tested. Grass SPPs inhibited 32 ± 0.06% of Lolium perenne Lol p 1 and 65% of Phleum pratense extracts, but results were highly variable for individual allergens (97.5%‐0.03% for Phl p 2, 45.3 ± 0.12% for Phl p 5, 24.7 ± 0.22% for Phl p 6, and 38.3 ± 0.2% for Phl p 1). Conclusions: Inhibition experiments confirm the hypothesis that SSPs obtained after the osmotic shock of pollen involved in TA, namely grass, pellitory and olive tree pollen, contain allergens and therefore they can induce severe asthma attacks during thunderstorms. [ABSTRACT FROM AUTHOR]

Purpose of Review: It is well known that combination of sensitization and exposure to inhaled environmental allergens is related to both the development and elicitation of symptoms of asthma and that avoidance of allergens would exert beneficial effects in the prevention and control of the disease. Other important factors include the relevance of other allergens, exposure to sensitizing agents also outside patient's home, exposure to irritants (like chemical air pollutants), and the involvement of the patient with a correct education. It is also likely that clinical phase of allergic airway disease and the degree of airways remodeling represent relevant factors for the clinical outcome of allergen avoidance procedure. We reviewed existing evidence on prevention of asthma through allergen avoidance. Recent Findings: The management of respiratory allergy is a complex strategy (including prevention, drugs, immunological, and educational interventions). In addition, it is difficult in real life to distinguish the efficacy of single interventions. However, a combined strategy is likely to produce clinical results. Summary: A combined strategy is likely to produce satisfactory management of asthma. Allergens are an important trigger factor for the development of symptoms of respiratory allergy, and avoidance measures are able to reduce allergen levels. It is likely that clinical phase of allergic airway disease and the degree of airways remodeling represents relevant factors for the clinical outcome of allergen avoidance procedures. Considering the management of respiratory allergy is a complex strategy; it is difficult in real life to distinguish the efficacy of single interventions. However, further studies better quantifying the effects of allergens are needed. [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the synergy between environmental factors (pollutant, allergenic birch pollen, weather) and its relationship with asthma hospitalization in Montreal, Canada. The data is stratified into weather types and the study restricted to spring season to limit the impact of multiple confounders. Results shows that the daily count of asthma hospitalization (spring 2006–2008) in situation of warm fronts or trowals (daily average of 3.78 counts, CI 95% 2.95–4.61) was much higher (p < 0.001) than in other situations (2.49 counts, CI 95% 2.37–2.71). Moreover, the explained variance of asthma hospitalization due to air pollution rises from about less than 7% (in the case of no stratification) to about 28% (R = 0.53, p < 0.05 with stratification). Statistical tests for interaction and overall results point towards a synergy between environmental factors which exacerbates asthma. A new concept named frontal asthma is proposed to explain several results found here and in the open literature. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reports of thunderstorm asthma in the Middle East are few. This study is the first to report on cases of near-fatal and fatal thunderstorm asthma in Kuwait on December 1, 2016. METHODS: We conducted a chart review and interview with adult patients admitted to Mubarak Al-Kabir Hospital with near-fatal asthma, defined as an exacerbation requiring intubation and mechanical ventilation or hypercapnia with a PaCO2≥6 kPa. Information, including patient age, gender, occupation, asthma history, medication usage, and clinical outcome, was collected. For fatal asthma cases, patients' data were collected from the Forensic Department at the Kuwait Ministry of Interior. RESULTS: A total of 17 patients were admitted with near-fatal asthma. Fifteen patients (93.8%) had a prior history of asthma, with an average duration of 9 years. Five patients (33.3%) reported receiving a corticosteroid inhaler from their physician. Fifteen patients (93.8%) reported relying on a short-acting β2-agonist alone to manage their asthma. Eleven patients (68.8%) reported being outdoors during the storm. Eleven patients were diagnosed with fatal asthma. CONCLUSION: The study is the first to report on a thunderstorm-associated asthma epidemic in Kuwait and emphasizes the potential dangers associated with this entity. [ABSTRACT FROM AUTHOR]

Background: The world's most catastrophic and deadly thunderstorm asthma epidemic struck Melbourne, Australia, on November 21, 2016. Objective: Among thunderstorm‐affected patients presenting to emergency rooms (ERs), we investigated risk factors predicting severe attacks requiring admission to hospital. Methods: Thunderstorm‐affected patients were identified from ER records at the eight major Melbourne health services and interviewed by telephone. Risk factors for hospital admission were analyzed. Results: We interviewed 1435/2248 (64%) of thunderstorm‐affected patients, of whom 164 (11.4%) required hospital admission. Overall, rhinitis was present in 87%, and current asthma was present in 28%. Odds for hospital admission were higher with increasing age (odds ratio 1.010, 95% CI 1.002, 1.019) and among individuals with current asthma (adjusted odds ratio [aOR] 1.87, 95% CI 1.26, 2.78). Prior hospitalization for asthma in the previous 12 months further increased the odds for hospital admission (aOR 3.16, 95% CI 1.63, 6.12). Among patients of Asian ethnicity, the odds for hospital admission were lower than for non‐Asian patients (aOR 0.59, 95% CI 0.38, 0.94), but higher if born in Australia (OR = 5.42, 95% CI 1.56, 18.83). Conclusions: In epidemic thunderstorm asthma patients who presented to the ER, higher odds for hospital admission among patients with known asthma were further amplified by recent asthma admission, highlighting the vulnerability conferred by suboptimal disease control. Odds for hospital admission were lower in Asian patients born overseas, but higher in Asian patients born locally, than in non‐Asian patients; these observations suggest susceptibility to severe thunderstorm asthma may be enhanced by gene‐environment interactions. We examined patients with acute asthma, who presented to Emergency Rooms during the 2016 Melbourne thunderstorm asthma epidemic. Patients with current asthma had higher odds (1.9) for hospital admission, hospitalization for asthma in the prior 12 months further increased the odds by 3.16. Among patients of Asian ethnicity, odds for hospital admission were lower than for non‐Asian patients (0.59), but higher if born in Australia (5.42), suggesting enhanced susceptibility from gene‐environment interactions. [ABSTRACT FROM AUTHOR]

Previous studies that described thunderstorm asthma, which is a rare event, are not being well explained. This study was conducted, to describe the patient perspective on their asthma attack experience during Ahvaz post-rain phenomenon. We have interviewed patients present in the Naft clinic of Ahvaz, during 28th October and the first week of November 2015. Recruitment was continued as saturation ensued by 33 participants. An inductive content analysis was used to evaluate the interviews. The key finding indicated a climatic condition, direct or indirect contact with rain, history of allergy, and physical conditions are the main categories. The patient emphasized the importance of dust, humidity, first autumn rainfall, and environmental air pollution in occurrences of the event. When exposed to further rains (third rainfall onward), they were less likely to experience dyspnea or shortness of breath. However, being indoor or out at the time of rainfall reported not to be related to the onset of asthma exacerbation. This study yielded that patients' asthma outbreak is a climate-related health impact and many individual factors triggering this issue. Patients concerns need future investigation and public health emergency planning and response arrangements. [ABSTRACT FROM AUTHOR]

We examine the seasonality of asthma-related hospital admissions in Melbourne, Australia, in particular the contribution and predictability of episodic thunderstorm asthma. Using a time-series ecological approach based on asthma admissions to Melbourne metropolitan hospitals, we identified seasonal peaks in asthma admissions that were centred in late February, June and mid-November. These peaks were most likely due to the return to school, winter viral infections and seasonal allergies, respectively. We performed non-linear statistical regression to predict daily admission rates as functions of the seasonal cycle, weather conditions, reported thunderstorms, pollen counts and air quality. Important predictor variables were the seasonal cycle and mean relative humidity in the preceding two weeks, with higher humidity associated with higher asthma admissions. Although various attempts were made to model asthma admissions, none of the models explained substantially more variation above that associated with the annual cycle. We also identified a list of high asthma admissions days (HAADs). Most HAADs fell in the late-February return-to-school peak and the November allergy peak, with the latter containing the greatest number of daily admissions. Many HAADs in the spring allergy peak may represent episodes of thunderstorm asthma, as they were associated with rainfall, thunderstorms, high ambient grass pollen levels and high humidity, a finding that suggests thunderstorm asthma is a recurrent phenomenon in Melbourne that occurs roughly once per five years. The rarity of thunderstorm asthma events makes prediction challenging, underscoring the importance of maintaining high standards of asthma management, both for patients and health professionals, especially during late spring and early summer. [ABSTRACT FROM AUTHOR]

Thunderstorm asthma and increased childhood leukemia risk near high-voltage power lines (HVPL) are occurrences whose mechanism of effect is not fully understood. This paper proposes and discusses a key similarity: both thunderstorms and HVPL generate a high enough electrical field in the environment to ionize nearby air and air-borne particles. I argue that the repeatedly demonstrated acute asthma response to pollen-laden air during thunderstorms is largely due to ionization of air-borne allergens, which adhere more readily and in greater quantity in the lungs than non-ionized particles. If these bind to mucous or phagocytic cells, it would enhance immune response. A rapid temperature drop and high ozone also seem to be drivers of thunderstorm asthma. This causal nexus provides strong support for the parallel situation of prolonged exposure to ionized particles near HVPL and an increased rate of childhood leukemia. Here, it is proposed that upwind carcinogens are ionized when passing HVPL and then residential and business areas. Published evidence for most steps are presented, but have not previously been published as a coherent whole, nor has it been suggested that the inhaled ionized micro-particle explanation for acute asthma may also explain development of childhood leukemia over time. The demonstrated series of events leading to increased deposition and retention of ionized particles in airways provides support for explaining both adverse health outcomes: acute thunderstorm asthma and increased risk of childhood leukemia near HVPL. Further support for this explanation of both outcomes is provided by effects of on-going proximity to highways. [ABSTRACT FROM AUTHOR]

The article explores thunderstorm asthma, the sudden increase in bronchospasm following a storm during pollen seasons. Particular focus is given to the rise in primary care facilities by general practitioner (GP) visits, emergency department (ED) admissions, and hospitalizations following these events. Additional topics discussed include research on thunderstorm asthma in Australia, specifically in the city of Melbourne, and accumulating evidence-based knowledge on the subject.

The fifth report issued by the Intergovernmental Panel on Climate Change forecasts that greenhouse gases will increase the global temperature as well as the frequency of extreme weather phenomena. An increasing body of evidence shows the occurrence of severe asthma epidemics during thunderstorms in the pollen season, in various geographical zones. The main hypotheses explaining association between thunderstorms and asthma claim that thunderstorms can concentrate pollen grains at ground level which may then release allergenic particles of respirable size in the atmosphere after their rupture by osmotic shock. During the first 20-30 min of a thunderstorm, patients suffering from pollen allergies may inhale a high concentration of the allergenic material that is dispersed into the atmosphere, which in turn can induce asthmatic reactions, often severe. Subjects without asthma symptoms, but affected by seasonal rhinitis can also experience an asthma attack. All subjects affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season, as such events may be an important cause of severe exacerbations. In light of these observations, it is useful to predict thunderstorms and thus minimize thunderstorm-related events. [ABSTRACT FROM AUTHOR]

The article looks at a study regarding meta-analyses endorse sublingual immunotherapy (SLIT) for grass pollen allergy with commercial pre- plus coseasonal or perennial regimens. It mentions preseasonal-only regimens would enhance adherence, cost–benefit, and risk reduction of adverse events but require efficacy comparable to longer courses and protection from epidemic thunderstorm asthma (ETA). It also mentions allergen-impregnated starch granules and mimicking aerosol challenge.

The article focuses on management of thunderstorm asthma in patients with seasonal allergic rhinoconjunctivitis or allergies to grass pollen and mentions aeroallergen interacts with antigen-presenting cells which leads to cognate T lymphocyte stimulation; and use of inhaled corticosteroid treatment.

Background: Exposure to the fungal allergen Alternaria alternata as well as ryegrass pollen has been implicated in severe asthma symptoms during thunderstorms. We have previously shown that Alternaria extract induces innate type 2 lung inflammation in mice. We hypothesized that the innate eosinophilic response to Alternaria extract may enhance lung inflammation induced by ryegrass. Methods: Mice were sensitized to ryegrass allergen and administered a single challenge with A. alternata extract before or after final ryegrass challenges. Levels of eosinophils, neutrophils, Th2 cells, innate lymphoid cells (ILC2), interleukin (IL)-5 and IL-13 in bronchoalveolar lavage (BAL) as well as inflammation and mucus were assessed. Results: Mice receiving ryegrass sensitization and challenge developed an eosinophilic lung response. A single challenge with Alternaria extract given 3 days before or 3 days after ryegrass challenges resulted in increased eosinophils, peribronchial inflammation and mucus production in the airways compared with ryegrass-only challenges. Type 2 ILC2 and Th2 cell recruitment to the airways was increased after Alternaria extract exposure in ryegrass-challenged mice. Innate immune challenges with Alternaria extract induced BAL eosinophilia, Th2 cell recruitment as well as ILC2 expansion and proliferation. Conclusions: A single exposure to Alternaria extract in ryegrass-sensitized and -challenged mice enhances the type 2 lung inflammatory response, including airway eosinophilia, peribronchial infiltrate, and mucus production, possibly through Th2 cell recruitment and ILC2 expansion. If translated to humans, exposure to both grass pollen and Alternaria may be a potential cause of thunderstorm-related asthma. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Thunderstorm asthma is a term used to describe an observed increase in acute bronchospasm cases following the occurrence of thunderstorms in the local vicinity. The roles of accompanying meteorological features and aeroallergens, such as pollen grains and fungal spores, have been studied in an effort to explain why thunderstorm asthma does not accompany all thunderstorms. Despite published evidence being limited and highly variable in quality due to thunderstorm asthma being a rare event, this article reviews this evidence in relation to the role of aeroallergens, meteorological features and the impact of thunderstorm asthma on health services. This review has found that several thunderstorm asthma events have had significant impacts on individuals’ health and health services with a range of different aeroallergens identified. This review also makes recommendations for future public health advice relating to thunderstorm asthma on the basis of this identified evidence. [ABSTRACT FROM AUTHOR]

Thunderstorms have been linked to asthma epidemics, especially during the pollen seasons, and there are descriptions of asthma outbreaks associated with thunderstorms, which occurred in several cities, prevalently in Europe (Birmingham and London in the UK and Napoli in Italy) and Australia (Melbourne and Wagga Wagga). Pollen grains can be carried by thunderstorm at ground level, where pollen rupture would be increased with release of allergenic biological aerosols of paucimicronic size, derived from the cytoplasm and which can penetrate deep into lower airways. In other words, there is evidence that under wet conditions or during thunderstorms, pollen grains may, after rupture by osmotic shock, release into the atmosphere part of their content, including respirable, allergen-carrying cytoplasmic starch granules (0.5–2.5 μm) or other paucimicronic components that can reach lower airways inducing asthma reactions in pollinosis patients. The thunderstorm-asthma outbreaks are characterized, at the beginning of thunderstorms by a rapid increase of visits for asthma in general practitioner or hospital emergency departments. Subjects without asthma symptoms, but affected by seasonal rhinitis can experience an asthma attack. No unusual levels of air pollution were noted at the time of the epidemics, but there was a strong association with high atmospheric concentrations of pollen grains such as grasses or other allergenic plant species. However, subjects affected by pollen allergy should be informed about a possible risk of asthma attack at the beginning of a thunderstorm during pollen season. [ABSTRACT FROM AUTHOR]

Over recent years, Australians have been subject to an unprecedented number of environmental events materially and visibly affecting air quality, including thunderstorm asthma and bushfire smoke. There is increasing evidence that poor air quality adversely affects health with consequences for mortality and morbidity with measured particulates (PM2.5) in January 2019 frequently exceeding World Health Organization standards. Biological factors can also impact air quality with thunderstorm asthma epidemics evidence of a prime example, the 2016 event being associated with severe impacts on health services. Given these events, consideration needs to be given to environmental health literacy which will support individuals with pre‐existing illness to recognise and mitigate as far as possible the effects of adverse air quality. Recognising the impact of poor air quality should also urge physicians to advocate for clean air as a necessity for good health. [ABSTRACT FROM AUTHOR]

Study objectives: To document the existence and investigate the etiology of "thunderstorm asthma," which has been reported sporadically over the past 20 years. Design: We assessed the relationship between thunderstorms, air pollutants, aeroallergens, and asthma admissions to a children's hospital emergency department over a 6-year period. Results: During thunderstorm days (n = 151 days) compared to days without thunderstorms (n = 919 days), daily asthma visits increased from 8.6 to 10 (p < 0.05), and air concentrations of fungal spores doubled (from 1,512 to 2,749/m³), with relatively smaller changes in pollens and air pollutants. Daily time-series analyses across the 6 years of observation, irrespective of the presence or absence of thunderstorms, demonstrated that an increase in total spores, equivalent to its seasonal mean, was associated with a 2.2% (0.9% SE) increase in asthma visits. Conclusions: Our results support a relationship between thunderstorms and asthma, and suggest that the mechanism may be through increases in spores that exacerbate asthma. Replication in other climates is suggested to determine whether these findings can be generalized to other aeroallergen mixes. [ABSTRACT FROM AUTHOR]