Is exposure to pollen a risk factor for moderate and severe asthma exacerbations?

Limited number of studies have focused on the impact of pollen exposure on asthma. As a part of the EAACI Guidelines on Environment Science, this first systematic review on the relationship of pollen exposure to asthma exacerbations aimed to bridge this knowledge gap in view of implementing recommendations of prevention. We searched electronic iPubMed, Embase, and Web of Science databases using a set of MeSH terms and related synonyms and identified 73 eligible studies that were included for systemic review. When possible, meta-analyses were conducted. Overall meta-analysis suggests that outdoor pollen exposure may have an effect on asthma exacerbation, but caution is needed due to the low number of studies and their heterogeneity. The strongest associations were found between asthma attacks, asthma-related ED admissions or hospitalizations, and an increase in grass pollen concentration in the previous 2-day overall in children aged less than 18 years of age. Tree pollen may increase asthma-related ED visits or admissions lagged up to 7-day overall in individuals younger than 18 years. Rare data show that among subjects under 18 years of age, an exposure to grass pollen lagged up to 3 days may lower lung function. Further research considering effect modifiers of pollen sensitization, hay fever, asthma, air pollution, green spaces, and pre-existing medications is urgently warranted to better evaluate the impacts of pollen on asthma exacerbation. Preventive measures in relation to pollen exposure should be integrated in asthma control as pollen increase continues due to climate change.

Diretriz Latino-americana sobre o Diagnóstico e Tratamento da Alergia Ocular ­ Em nome da Sociedade Latinoamericana de Alergia, Asma e Imunologia (SLAAI) / Latin American Guideline on the Diagnosis and Treatment of Ocular Allergy ­ On behalf of the Latin American Society of Allergy, Asthma and Immunology (SLAAI)

A alergia ocular, também conhecida como conjuntivite alérgica (CA), é uma reação de hipersensibilidade mediada por imunoglobulina E (IgE) do olho desencadeada por aeroalérgenos, principalmente ácaros da poeira doméstica e pólen de gramíneas. Os sintomas geralmente consistem em prurido ocular ou periocular, lacrimejamento e olhos vermelhos que podem estar presentes durante todo o ano ou sazonalmente. A alergia ocular tem frequência elevada, é subdiagnosticada e pode ser debilitante para o paciente. É potencialmente danosa para a visão, nos casos em que ocasiona cicatrização corneana grave, e na maioria dos pacientes associa-se a outros quadros alérgicos, principalmente rinite, asma e dermatite atópica. É classificada em conjuntivite alérgica perene, conjuntivite alérgica sazonal, ceratoconjuntivite atópica e ceratoconjuntivite vernal. O diagnóstico procura evidenciar o agente etiológico e a confirmação se dá pela realização do teste de provocação conjuntival. O tratamento baseia-se em evitar o contato com os desencadeantes, lubrificação, anti-histamínicos tópicos, estabilizadores de mastócitos, imunossupressores e imunoterapia específica com o objetivo de obter o controle e prevenir as complicações da doença.

Ocular allergy, also known as allergic conjunctivitis, is an immunoglobulin E-mediated hypersensitivity reaction of the eye triggered by airborne allergens, primarily house dust mites and grass pollen. Symptoms usually consist of ocular or periocular itching, watery eyes, and red eyes that may be present year-round or seasonally. Ocular allergy has a high frequency, is underdiagnosed, and can be debilitating for the patient. It is potentially harmful to vision in cases of severe corneal scarring, and in most patients, it is associated with other allergic conditions, especially rhinitis, asthma, and atopic dermatitis. It is classified as perennial allergic conjunctivitis, seasonal allergic conjunctivitis, atopic keratoconjunctivitis, and vernal keratoconjunctivitis. Diagnosis seeks to identify the etiologic agent, and confirmation is given by conjunctival provocation testing. Treatment is based on avoiding contact with triggers, lubrication, topical antihistamines, mast cell stabilizers, immunosuppressants, and specific immunotherapy with the aim of achieving control and preventing disease complications.

Preventive home therapy for symptomatic patients affected by COVID-19 and followed by teleconsultations.

In this paper we present our experience on the treatment at home of Covid+ symptomatic patients. One hundred and eighty-two subjects (111 men and 71 women) aged from 32 to 71 years have been consecutively followed at home in telemedicine from 1st September to 24th December 2020. We were informed almost twice daily in morning and evening about body temperature, symptoms (cough, shortness of breath or difficulty breathing, fatigue, muscle of body aches, headache, loss of taste or smell, sore throat, congestion or runny nose, nausea and vomiting, diarrhea), oxygen saturation measured by digital pulse oximetry and blood pressure. Our protocol of treatment was based on early use of prednisone (25 mg in the morning and 12.5 mg in the afternoon) and low molecular weight heparin (4000 UI one or two times daily) initiated just after the positivity of molecular nasopharyngeal test (about 3-4 days as mean time after initiation of symptomatology and not after 7-8 days as suggested by other protocols) and oxygen therapy when necessary. Antibiotics such as azithromycin for six days was added. It is always recommended to associate lansoprazole 30 mg to prevent gastric hemorrhages and potassium and magnesium supplements. This treatment scheme was able to reduce the risk of hospitalization as only 4 patients needed to be admitted to the Hospital, and only two in subintensive department. After negativeness of molecular nasopharyngeal test, patients were invited for a thoracic computerized tomography and laboratory evaluation of d-dimer and other data of inflammation to show eventual lung interstitial involvement characteristic of COVID-19.

The effects of climate change on respiratory allergy and asthma induced by pollen and mold allergens.

The impact of climate change on the environment, biosphere, and biodiversity has become more evident in the recent years. Human activities have increased atmospheric concentrations of carbon dioxide (CO2 ) and other greenhouse gases. Change in climate and the correlated global warming affects the quantity, intensity, and frequency of precipitation type as well as the frequency of extreme events such as heat waves, droughts, thunderstorms, floods, and hurricanes. Respiratory health can be particularly affected by climate change, which contributes to the development of allergic respiratory diseases and asthma. Pollen and mold allergens are able to trigger the release of pro-inflammatory and immunomodulatory mediators that accelerate the onset the IgE-mediated sensitization and of allergy. Allergy to pollen and pollen season at its beginning, in duration and intensity are altered by climate change. Studies showed that plants exhibit enhanced photosynthesis and reproductive effects and produce more pollen as a response to high atmospheric levels of carbon dioxide (CO2 ). Mold proliferation is increased by floods and rainy storms are responsible for severe asthma. Pollen and mold allergy is generally used to evaluate the interrelation between air pollution and allergic respiratory diseases, such as rhinitis and asthma. Thunderstorms during pollen seasons can cause exacerbation of respiratory allergy and asthma in patients with hay fever. A similar phenomenon is observed for molds. Measures to reduce greenhouse gas emissions can have positive health benefits.

Differences in Reporting the Ragweed Pollen Season Using Google Trends across 15 Countries.

BACKGROUND: Google Trends (GT) searches trends of specific queries in Google, which potentially reflect the real-life epidemiology of allergic rhinitis. We compared GT terms related to ragweed pollen allergy in American and European Union countries with a known ragweed pollen season. Our aim was to assess seasonality and the terms needed to perform the GT searches and to compare these during the spring and summer pollen seasons. METHODS: We examined GT queries from January 1, 2011, to January 4, 2017. We included 15 countries with a known ragweed pollen season and used the standard 5-year GT graphs. We used the GT translation for all countries and the untranslated native terms for each country. RESULTS: The results of "pollen," "ragweed," and "allergy" searches differed between countries, but "ragweed" was clearly identified in 12 of the 15 countries. There was considerable heterogeneity of findings when the GT translation was used. For Croatia, Hungary, Romania, Serbia, and Slovenia, the GT translation was inappropriate. The country patterns of "pollen," "hay fever," and "allergy" differed in 8 of the 11 countries with identified "ragweed" queries during the spring and the summer, indicating that the perception of tree and grass pollen allergy differs from that of ragweed pollen. CONCLUSIONS: To investigate ragweed pollen allergy using GT, the term "ragweed" as a plant is required and the translation of "ragweed" in the native language needed.

How Do Storms Affect Asthma?

PURPOSE OF REVIEW: There are observations in various geographical areas that thunderstorms occurring during pollen seasons can induce severe asthma attacks in pollinosis patients. RECENT FINDINGS: An accredited hypothesis explaining the association between thunderstorms and asthma suggests that storms can concentrate pollen grains at ground level, which may then release allergenic particles of respirable size in the atmosphere after their imbibition of water and rupture by osmotic shock. During the first 20-30 min of a thunderstorm, patients affected by pollen allergy may inhale a high quantity of the allergenic material that is dispersed into the atmosphere as a bioaerosol of allergenic particles, which can induce asthmatic reactions, often severe. Subjects without asthma symptoms, but affected by seasonal rhinitis can also experience an asthma attack. A key message is that 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 asthma exacerbations. In light of these observations, it is useful to predict thunderstorms and thus minimize thunderstorm-related events. Patients with respiratory allergy induced by pollens and molds need to be informed about a correct therapeutic approach of bronchial asthma by inhalation, including the use of bronchodilators and inhaled corticosteroids. The purpose of this review is to focalize epidemiological, etiopathogenetic, and clinical aspects of thunderstorm-related asthma.

[Thunderstorm and asthma outbreaks during pollen season]. / Temporali e attacchi d'asma durante le stagioni polliniche.

An increasing body of evidence shows the occurrence of asthma epidemics, sometimes also severe, during thunderstorms in the pollen season in various geographical zones. The main hypothesis explaining association between thunderstorms and asthma claims that thunderstorms can concentrate pollen grains at ground level; these grains may then release allergenic particles of respirable size in the atmosphere after their rupture by osmotic shock. During the first 20-30 minutes of a thunderstorm, patients suffering from pollen allergy may inhale a high concentration of the allergenic material dispersed into the atmosphere, which can, in turn, 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 bronchial obstruction. Considering this background, it is useful to predict thunderstorms during pollen season and, thus, to prevent thunderstorm-related clinical event. However, it is also important to focus on therapy, and it is not sufficient that subjects at risk of asthma follow a correct therapy with bronchodilators, but they also need to inhale corticosteroids, using both in case of emergency.

The dangerous liaison between pollens and pollution in respiratory allergy.

OBJECTIVE: To recapitulate the more recent epidemiologic studies on the association of air pollution with respiratory allergic diseases prevalence and to discuss the main limitations of current approaches used to establish a link between pollinosis and pollution. DATA SOURCES: Through the use of PubMed, we conducted a broad literature review in the following areas: epidemiology of respiratory allergic diseases, effect of pollution and climate changes on pollen grains, and immunomodulatory properties of pollen substances. STUDY SELECTIONS: Studies on short- and long-term exposure to air pollutants, such as gaseous and particulate materials, on allergic sensitization, and on exacerbation of asthma symptoms were considered. RESULTS: Trend in respiratory allergic disease prevalence has increased worldwide during the last 3 decades. Although recent epidemiologic studies on a possible association of this phenomenon with increasing pollution are controversial, botanic studies suggest a clear effect of several pollutants combined to climatic changes on the increased expression of allergenic proteins in several pollen grains. The current literature suggests the need for considering both pollen allergen and pollutant contents for epidemiologic evaluation of environmental determinants in respiratory allergies. We propose that a measure of allergenic potential of pollens, indicative of the increase in allergenicity of a polluted pollen, may be considered as a new risk indicator for respiratory health in urban areas. CONCLUSION: Because public greens are located in strict proximity to the anthropogenic sources of pollution, the identification of novel more reliable parameters for risk assessment in respiratory allergic diseases is an essential need for public health management and primary prevention area.

Nasal rinsing with an atomized spray improves mucociliary clearance and clinical symptoms during peak grass pollen season.

BACKGROUND: Nasal rinsing with an atomizer spray was found to be effective in the treatment of allergic rhinitis. Two parameters express the nasal functions: (1) mucociliary clearance (MCC), and (2) the pH and its stability. MCC is the main factor that defines the time of pollen transition on the nasal mucosa and, therefore, the amount of the allergen glycoprotein elution. OBJECTIVE: We hypothesized that the nasal wash efficacy could be due to the reduction of contact time of the grass pollen on the nasal mucosa (improving MCC). METHODS: Forty patients with seasonal grass pollen oculorhinitis were randomized in two groups: 20 received three times daily nasal rinsing with hypertonic solution buffered to pH 6.1, before and during the peak pollen season in 2015 (active group), and another 20 patients were allocated to the control group and received no nasal treatment. The daily symptoms score and the use of oral antihistamines when required were evaluated during the grass pollen peak season. All the patients completed the study. RESULTS: In comparison with the control group, in the active group, a significant decrease of both nasal symptoms (p = 0.01) and consumption of antihistamines (p = 0.035) was found. Furthermore, the MCC was significantly worse (p = 0.011) only in the control group. CONCLUSION: The nasal treatment maintained the efficiency of the MCC in the patients in the active group, who showed a significant reduction of symptoms and medication score. The MCC decreased the transit time of the pollen on the nasal mucosa, which favored an elution of the allergenic proteins.

Climate change, air pollution, and allergic respiratory diseases: an update.

PURPOSE OF REVIEW: The rising trend in prevalence of allergic respiratory disease and bronchial asthma, observed over the last decades, can be explained by changes occurring in the environment, with increasing presence of biologic, such as allergens, and chemical atmospheric trigger factors able to stimulate the sensitization and symptoms of these diseases. RECENT FINDINGS: Many studies have shown changes in production, dispersion, and allergen content of pollen and spores because of climate change with an increasing effect of aeroallergens on allergic patients. SUMMARY: Over the last 50 years, global earth's temperature has markedly risen likely because of growing emission of anthropogenic greenhouse gas concentrations. Major changes involving the atmosphere and the climate, including global warming induced by human activity, have a major impact on the biosphere and human environment.Urbanization and high levels of vehicle emissions are correlated to an increase in the frequency of pollen-induced respiratory allergy prevalent in people who live in urban areas compared with those who live in rural areas. Measures of mitigation need to be applied for reducing future impacts of climate change on our planet, but until global emissions continue to rise, adaptation to the impacts of future climate variability will also be required.

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen.

Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O(3)) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O(3) fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O(3) fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O(3), determined from the mRNA levels of the major allergens. We conclude that O(3) can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase.

Short-term effects of airborne pollens on asthma attacks as seen by general practitioners in the Greater Paris area, 2003-2007.

AIMS: To investigate for the first time the short-term effects of airborne pollen counts on general practitioner (GP) consultations for asthma attacks in the Greater Paris area between 2003-2007. METHODS: Counts were available for common pollens (Betula, Cupressa, Fraxinus and Poaceae). Weekly data on GP visits for asthma attacks were obtained from the French GP Sentinel Network. A quasi-Poisson regression with generalised additive models was implemented. Short-term effects of pollen counts were assessed using single and multi-pollen models after adjustment for air pollution and influenza. RESULTS: A mean weekly incidence rate of 25.4 cases of asthma attacks per 100,000 inhabitants was estimated during the study period. The strongest significant association between asthma attacks and pollen counts was registered for grass (Poaceae) in the same week of asthma attacks, with a slight reduction of the effect observed in the multi-pollen model. Adjusted relative risk for Poaceae was 1.54 (95% CI: 1.33-1.79) with an inter-quartile range increase of 17.6 grains/m3 during the pollen season. CONCLUSIONS: For the first time, a significant short-term association was observed between Poaceae pollen counts and consultations for asthma attacks as seen by GPs. These findings need to be confirmed by more consistent time-series and investigations on a daily basis.

Environmental urban factors (air pollution and allergens) and the rising trends in allergic respiratory diseases.

Respiratory allergic diseases such as rhinitis and bronchial asthma appear to be increasing worldwide, affecting in particular subjects living in urban areas, and the reasons for this increase are still largely unknown. Although the role played by air pollution has yet to be clarified, a body of evidence suggests that urbanization, with its high levels of vehicle emissions and a westernised lifestyle are linked to the rising frequency of these diseases observed in most industrialized countries. Laboratory studies confirm the epidemiological evidence that inhalation of some pollutants, either individually or in combination, adversely affect lung function in asthmatics. Air pollutants may not only increase the frequency and intensity of symptoms in already allergic patients but may promote airway sensitization to airborne allergens in predisposed subjects. By attaching to the surface of pollen grains and of plant-derived paucimicronic particles, pollutants can modify the morphology of these antigen-carrying agents and alter their allergenic potential. In addition, by inducing airway inflammation, pollutants may overcome the mucosal barrier and so "prime" allergen-induced responses. In other words airway mucosal damage and impaired mucociliary clearance induced by air pollution may facilitate the access of inhaled allergens to the cells of the immune system.