Pollen Season Research Articles (Page 1)

Pollen hydration and its induced effects on human bronchial epithelial cells: A comparative analysis of three species.

Objective: This study aimed to evaluate the demographic and clinical features of pediatric aeroallergen sensitization and seasonal symptom patterns, focusing on pollen. Materials and methods: This retrospective single-center study included children aged 1–18 years who underwent standardized skin prick testing (SPT) between January 2020 and July 2021. Patients with chronic or immunological disorders other than asthma, allergic rhinitis (AR), and atopic dermatitis (AD) were excluded. Clinical and laboratory data, including symptom profiles, family atopy history, eosinophil counts, and total IgE, were extracted from records. Aeroallergen panels included pollens, house dust mites, molds, and animal dander. Comparisons were performed between monosensitized and polysensitized patients, and between those sensitized to pollen versus house dust mites. Results: Of 2247 children tested, 2017 were eligible, and 500 (24.7%) with clinically relevant sensitization were analyzed (57% male; median age: 12 years, IQR: 8–15). Pollen was the most frequent sensitizer (78.6%), followed by house dust mites (36.6%). Within pollens, Poaceae predominated (98.1%), with Secale as the leading species (88.4%). Seasonal peaks of symptoms in pollen-sensitized patients occurred in May (31.8%), April (29.6%), and June (27%). Polysensitization was observed in 38.8%. AR was the most common diagnosis (83.2%), while asthma and AD were present in 36.4% and 34.0%, respectively. Pollen sensitization was significantly associated with AR (88% vs. 63%, p < 0.01) and sneezing (38% vs. 16%, p < 0.01), whereas house dust mite sensitization was more often linked with skin rashes (25.5% vs. 13%, p = 0.008). Patients with eosinophilia were younger, predominantly male, and more frequently diagnosed with AR (p < 0.001). Conclusions: Pollen, particularly from the Poaceae family, was the predominant aeroallergen, and symptom timing matched seasonal pollen trends. Inclusion of region-specific pollens such as Secale in SPT panels is crucial for accurate sensitization detection and for guiding localized public health strategies.

The search for new safe and effective methods of immunomodulatory treatment that will prevent the exacerbation of the disease, the development of exacerbations and complications remains a priority task of modern allergology and immunology. This article presents current data on the possibilities of nonspecific immunotropic therapy with the drug Ruzam in the treatment of allergic diseases, including in immunocompromised patients. The drug Ruzam performs endogenous regulation of processes aimed at eliminating immunological dysfunction and suppressing allergic inflammation by influencing cellular and humoral immune responses and nonspecific resistance of the body through the regulation of key cytokines, polarizing the immune response from Th2 to Th1 cells, and reducing the level of IgE in the blood. Due to its universal anti-inflammatory effect, the drug Ruzam has established itself as the first-line drug of choice in patients with AD—the number of exacerbations and their severity decreased during the pollination period of causally significant plants, and the total amount of pharmacological assistance required during the pollen season also decreased. The clinical efficacy of the drug Ruzam in patients with asthma has been confirmed: the intensity and severity of asthma attacks decreased, the amount of drug therapy was reduced by half during treatment, and the duration of remission increased to an average of 2—3 years. The efficacy of Ruzam in AR has been confirmed by its positive therapeutic effect on all major symptoms of AR. The clinical efficacy of Ruzam in patients with AD has been confirmed in studies—compared to placebo, Ruzam significantly reduces the SCORAD index (by 58.93%) and the duration of relapses (by 40%) in patients with mild to moderate AD.

Daily pollen concentrations were monitored from August to October 2023, concurrently with meteorological data and air quality indices. Clinical data, including symptoms and fractional exhaled nitric oxide (FENO) levels, were collected from 61 PiAR patients to evaluate the impact of environmental factors on allergy severity and airway inflammation. Among meteorological variables, temperature exhibited a positive influence on the concentrations of total pollen, specifically that of Artemisia, Humulus, and Chenopodium pollen, while air pressure showed an inverse relationship. Regarding air pollutants, O3 concentration was positively associated with Artemisia pollen levels, whereas CO and NO2 were negatively associated. Statistical analysis demonstrated a strong positive correlation between daily weed pollen concentrations and the Combined Symptom and Medication Score (CSMS) (r = 0.81, p < 0.0001), as well as between weekly average pollen concentrations and the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score (r = 0.95, p < 0.0001). Pollen exposure showed a significant immediate effect on CSMS at lag 0 (EE = 0.205, 95% CI: 0.076-0.334), while air pressure exhibited significant lagged and cumulative effects during lag days 0-5 (EE = 0.815, 95% CI: 0.337-1.293). Notably, the interaction between temperature and air pressure was also statistically significant (p < 0.001). Additionally, FENO levels in PiAR patients significantly rose during the peak weed pollen season (p < 0.001), indicating elevated airway inflammation. This study highlights the complex interplay between meteorological factors, air pollutants, and pollen in exacerbating allergic symptoms. The findings underscore the need for integrated environmental and clinical management strategies to mitigate the burden of PiAR in urban settings.

Climate change is currently the greatest global health threat. As the planet experiences rising temperatures due to global warming, widespread health impacts are emerging, including extreme weather events, food insecurity due to droughts, and forced relocation of populations. From a respiratory health perspective, patients with lung disease experience negative health consequences due to high temperatures, risks from heat-related illnesses, exposure to wildfire smoke that causes poor air quality, and increased severity and duration of pollen seasons. The resulting health consequences contribute to increased use of healthcare services, which in turn generate their own contributions to healthcare pollution, thus further worsening the climate crisis. In fact, the health sector contributes more than 5.2% of net global greenhouse gas emissions. In Canada, healthcare activities are responsible for 4.6% of the country’s total greenhouse gas emissions, placing Canada’s healthcare system among the top four emitters per capita by country. In terms of the contributions of various healthcare sectors to greenhouse gas emissions, England’s National Health Service (NHS) demonstrated that anesthetic gases and metered dose inhalers (MDIs) play a significant role; MDIs alone contribute to 3.1% of the NHS’s total healthcare emissions. MDIs rely on hydrofluorocarbon (HFC) propellants to deliver medication, which act as potent greenhouse gases when released into the atmosphere. Depending on the formulation, one aerosol inhaler can have a carbon footprint equivalent to driving a gasoline-powered car up to 170 km. In Canada, short-acting beta-agonist (SABA) inhalers constitute 71% of total inhaler use, the majority of which are delivered via MDI devices. For these reasons, strategies that reduce the use of MDIs have the potential to reduce negative environmental consequences of respiratory care.

Asian sand dust (ASD), a type of fine particulate matter originating from arid regions of East Asia, is known to exacerbate respiratory diseases, but its impact on the ocular surface remains poorly understood. Given the increasing prevalence of allergic conjunctivitis in Japan, particularly during the Japanese cedar pollen (JCP) season, we investigated whether ASD exposure aggravates ocular allergic inflammation. Using a mouse model sensitized with JCP, we found that conjunctival instillation of ASD in combination with JCP significantly increased clinical signs such as hyperemia and edema, along with elevated serum IgE levels and enhanced inflammatory cell infiltration compared to JCP alone. Histological analysis revealed epithelial disruption and increased infiltration of CD3-positive T cells and F4/80-positive macrophages in the ASD/JCP group. These findings demonstrate that ASD exacerbates allergic conjunctivitis by amplifying inflammatory responses on the ocular surface. Our study highlights ASD as a potential environmental risk factor for allergic eye diseases and offers novel mechanistic insights into how airborne pollutants interact with allergen-induced ocular inflammation.

Background: The CAMS Regional System provides crucial, reliable pollen forecasts for allergenic pollen types. These robust predictions support the scientific and medical communities, aiding in the diagnosis, evaluation, and protection of allergic populations. So, the main goal of this study was to evaluate which model, or models best represent and simulate the olive and grass pollen data of the Évora region in the years 2021 to 2024. Results: The results showed that there are statistically significant differences between the data of the models and between the years for each of the pollen types considered. These differences were not just in pollen concentrations; they also appeared in characteristics of the pollen season, like its duration, maximum peak concentration, start date and exposure level. According to Taylor diagrams, applying moving average for normalized data, it was shown that MOCAGE best represents and simulates olive concentration data. For grass pollen SILAM, EURAD-IM and MOCAGE were the best performers. Conclusions: CAMS data can enhance the quality of life of the allergic population, as well as support the scientific and medical community to improve, assist and create mitigation measures that reduce exposure and consequently significantly reduce the occurrence of allergic disease.

Decreasing annual pollen loads in evergreen needleleaf species (Pinaceae) by the earlier end of the spring pollen season

Background:Hay fever cases, driven by factors such as global warming, are increasing globally, with Japanese cedar (JC) pollen being the primary allergen in Japan. While pharmacological therapies are available, their success heavily depends on patients’ preventive behaviors, which remain poorly documented. This study examines the relationship between symptom severity and preventive behaviors during the JC pollen season.Design and methods:This single-center, observational study included 161 new patients diagnosed with JC pollen allergy from January to March 2017. Patient data were collected through interviews and analyzed for severity using a five-point symptom scale and total Nasal Symptom Scores. Preventive behaviors, including preemptive antihistamine use, allergen immunotherapy, and pre-season consultations, were evaluated. Time-series analysis assessed trends in severe cases over the pollen season.Results:Patients who sought pre-season consultations were predominantly male (p = 0.006) and more likely to use preemptive antihistamines (p < 0.001) or allergen immunotherapy (p = 0.006). Severe symptoms were recorded in 38 patients, none of whom engaged in preventive behaviors, and only 10.5% sought pre-season consultations. Time-series analysis showed a daily increase of 6% severe cases after pollen season onset (p = 0.0064). Early preventive behaviors, such as preemptive antihistamine use (p = 0.007) and pre-season consultations (p < 0.001), significantly reduced severe cases.Conclusions:The study highlights the importance of early preventive measures to reduce symptom severity and improve patient outcomes. Promoting preventive behaviors could alleviate the growing economic burden of hay fever and enhance public health strategies globally.

This paper explores the application of the One Health framework to atopic dermatitis (AD), a complex, chronic skin disease, emphasizing interdisciplinary approaches to prevention and management. One Health integrates human, animal, environmental, and plant health, addressing challenges such as antimicrobial resistance, infectious diseases, and neglected tropical diseases (NTDs). In the context of AD, One Health principles are applied to explore etiological factors like urbanization, climate change, biodiversity loss, and environmental pollution. Key findings include the interplay between lifestyle and environmental exposures, as evidenced by studies on human-dog microbiota sharing, which reveal that rural environments confer protective effects against allergic conditions for both species. Historical observations of the "old farm effect" highlight the protective role of traditional rural living, including raw milk consumption, in preventing atopic diseases. However, modern urbanization and industrial farming have eroded these benefits. Climate change intensifies AD symptoms through extreme weather, proliferation of more and higher allergenic pollen, likely also of house dust mites, allergen proliferation, and pollution. Rising CO2 levels exacerbate pollen allergenicity, prolong pollen seasons, and amplify allergic responses. The skin's microbiome and immune barrier are sensitive to pollutants like black carbon and traffic-related emissions, further influencing AD prevalence and severity. Innovative approaches to prevention, such as veterinary vaccination strategies targeting allergens or immunopathological key cytokines, illustrate cross-species solutions. Web data mining demonstrates potential for analyzing public interest and seasonal trends in AD, correlating search data with real-time monitored environmental factors and highlighting gaps in awareness and access to modern treatments. This integrative One Health lens provides a framework for reimagining AD prevention and management, emphasizing a return to environmental and lifestyle diversity, climate action, and leveraging digital and biomedical tools for personalized, sustainable care.

Introduction: Artemisia pollen is a major aeroallergen source in Northern China that can cause multiple kinds of common allergic diseases. China’s first Artemisia annua sublingual drops for Artemisia pollen-induced seasonal allergic rhinitis were launched in 2021. This study aimed to evaluate the efficacy and safety of a 2-year course of sublingual immunotherapy (SLIT) using A. annua allergen extract in patients with seasonal allergic rhinoconjunctivitis (SARC). Additionally, it sought to assess the sustained clinical efficacy of this therapy 1 year post-treatment. Methods: Fifty patients (aged 4–60 years) with SARC and confirmed A. annua pollen allergy were enrolled in this study. In accordance with their preferences, the subjects were assigned to either the SLIT group (n = 25, receiving SLIT plus symptomatic treatment) or the control group (n = 25, receiving symptomatic treatment alone) at a ratio of 1:1. The entire study lasted for 3 years, initiating a 2-year treatment phase (2022 and 2023 pollen seasons) followed by a 1-year post-discontinuation follow-up period (2024 pollen season), with 2021 pollen season regarded as baseline. The total rhinoconjunctivitis symptom score (TRSS), total medication score (TMS), combined score of medication and rhinoconjunctivitis symptoms (CSMRS), and visual analogue scale (VAS) were compared between the two groups for clinical efficacy. In addition, the rhinoconjunctivitis quality of life questionnaire (RQLQ) was used to assess the impact of the A. annua SLIT on the quality of life of patients. Safety was evaluated based on adverse events. Results: A total of 41 patients completed the study (SLIT: n = 21, control: n = 20). There were no significant differences between the two groups during 2021 pollen season (baseline). However, the scores of TRSS (all p < 0.001), CSMRS (all p < 0.001), VAS (2022: p < 0.01; 2023: p < 0.001; 2024: p < 0.001), and RQLQ scores (2022: p < 0.01; 2023: p < 0.001; 2024: p < 0.001) were significantly lower than the control group during the 2-year SLIT treatment period and 1-year follow-up period. For TMS scores, although no statistically significant differences were found in 2022 and 2023 pollen seasons (p > 0.05), the SLIT group showed a decreasing trend. And TMS of SLIT group was significantly lower than that of the control group during 2024 pollen season (p < 0.05). In addition, RQLQ scores correlated positively with CSMRS and VAS (all p < 0.001). Conclusions: A 2-year course of SLIT with A. annua allergen extract significantly alleviated symptoms and reduced medication use in SARC patients, with clinical benefits persisting for at least 1-year post-treatment phase.

Evidence supports the hypothesis of pollen-induced asthma as a specific asthma phenotype, with defined clinical features and tailored pathways for its clinical management. The probability of diagnosis varies significantly in the pollen season, in which allergic patients are symptomatic, as compared to asymptomatic periods outside the pollen season. In this context, a novel diagnostic scheme for pollen-induced asthma has been developed. Pollen exposure is the key risk factor for symptoms and exacerbations. Therefore, we proposed a therapeutic algorithm for pollen-induced asthma based on a risk stratification model that considers the medical history of the patients and the measurement of objective markers, allowing a tailored therapeutic approach.

A Wideband Integrated Bioaerosol Sensor (WIBS) was used in conjunction with chemical tracer analysis for the first time during the 2022–2023 grass pollen season in Melbourne, Australia. WIBS detected continuous levels of bioaerosol throughout the campaign. From 18th November to 7th December 2022, fluorescent particles accounted for an average of 10% of total particles in number, corresponding to an estimated 0.18 μg m−3 PM2.5 (14%) and 0.49 μg m−3 PM10 (25%). Using mannitol as a chemical tracer, fungal spores were estimated to contribute to an average of 2% of PM2.5 and 9% of PM10 mass. Analysis of fructose in PM2.5 as a marker for sub-pollen particles (SPPs) showed elevated concentrations during periods of hot and dry weather. There was negligible fructose observed with rain, suggesting that SPP production is not limited to water absorption processes or high relative humidity in Melbourne. Estimates of SPP mass via fructose corresponded to the equivalent of 1.1 m−3 intact pollen grains on average, 2% of the total pollen concentration, 7% of PM2.5 fluorescent particle mass, and 1% of PM2.5 mass. New hourly measured grass pollen data confirmed the timing and magnitude of grass pollen emissions in the Victorian Grass Pollen Emission Model (VGPEM) and captured the strong diurnal variation. Five grass pollen rupturing mechanisms using different meteorological drivers were tested against the WIBS and fructose measurements. Whilst the WIBS and model were not well correlated, likely due to the complex mixture of bioaerosols and low relative abundance of SPPs, the mechanical wind speed rupturing mechanism represented the fructose time series well. Conceptually, this suggests that mechanical rupturing describes SPP formation during hot and dry conditions in Melbourne. Long-term measurements in Melbourne will improve SPP formation process forecasting.

BackgroundEnvironmental exposure chambers (EECs) provide a controlled and reproducible setting for studying allergic rhinitis, allowing standardized exposure to aeroallergens. However, real-time symptom monitoring remains challenging, particularly as patients must be observed remotely while inside the chamber.ObjectiveThis study aimed to design, implement, and evaluate an integrated eHealth system that leverages digital tools for data collection and real-time clinical monitoring during EEC exposures. The goal was to streamline workflow, enhance data reliability, and improve patient safety during allergen challenges.MethodsWe conducted a prospective pilot study in a validated EEC at Ramón y Cajal University Hospital. A total of 34 provocation tests were conducted: 27 in patients with confirmed grass pollen allergy and 7 in nonallergic controls. All exposures took place outside the pollen season using standardized Phleum pratense (grass pollen) at concentrations of 940±100 grains/m³. Clinical data were collected using REDCap (Research Electronic Data Capture; Vanderbilt University), a secure electronic data capture platform. Surveys were automatically scheduled and included standardized instruments: Visual Analog Scale (VAS), Total Nasal Symptom Score (TNSS), Total Ocular Symptom Score (TOSS), asthma symptom questionnaires, peak expiratory flow (PEF), and peak nasal inspiratory flow (PNIF). Data were visualized in real time using Power BI dashboards (Microsoft Corp).ResultsAmong allergic patients, 85% had a positive response to the allergen exposure, with a median TNSS of 6 (IQR 6‐7), while controls showed no positive reactions. Mean exposure time for positive cases was 48.9 minutes (SD 28.3), as patients were withdrawn early upon reaching symptom thresholds. The REDCap system was configured to collect symptom surveys at 15-minute intervals, allowing up to 6 entries per patient during exposure, depending on clinical tolerance. This setup enabled consistent symptom monitoring and integration with Power BI for real-time visualization. All records were successfully synchronized between REDCap and Power BI. Informal feedback from medical staff highlighted improved workflow and usability.ConclusionsThe integration of REDCap with Power BI enabled automated, real-time tracking of symptoms during EEC exposures. This eHealth solution enhanced clinical oversight, supported timely decision-making, and ensured patient safety. The platform provides a flexible and reproducible model for use in allergen exposure studies and other clinical settings requiring structured remote monitoring. Clinical response data are reported in a separate validation study.

IntroductionFood-induced anaphylactic shock is the most severe and life-threatening manifestation of food allergy in children. However, its underlying risk factors remain poorly defined, especially in pediatric populations. This study aimed to identify independent predictors of food-induced anaphylactic shock by analyzing clinical and immunological data from a tertiary hospital in Northern China.MethodsThis retrospective study included 68 children (aged 0–16 years) hospitalized for food-induced anaphylaxis at Peking University Third Hospital from May 2018 to May 2025. Demographic data, clinical manifestations, serum-specific immunoglobulin E (sIgE) levels, and comorbidities were collected. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of anaphylactic shock.ResultsOf 68 patients with food-induced anaphylaxis, 14 (20.6%) experienced anaphylactic shock, with 78.6% of these cases occurring in children older than six years. Wheat and fruits were the most common triggers in the shock group (each 28.6%). Subgroup analysis revealed that 88.9% (8/9) of plant-food-triggered shock cases specifically clustered from April to October, aligning with mugwort pollen season. sIgE levels to inhalant allergens, especially mugwort, were significantly higher in the shock group (P < 0.05). In multivariate analysis, mugwort sensitization (sIgE levels exceeding 2.83 kU/L, OR = 9.91, 95% CI: 1.27–77.31, P = 0.029) and comorbid asthma (OR = 8.11, 95% CI: 1.29–50.98, P = 0.026) were identified as independent predictors of anaphylactic shock.ConclusionsMugwort sensitization and asthma are independent risk factors for food-induced anaphylactic shock in children. Early identification of these risk markers may support early risk stratification and seasonal dietary interventions.

BACKGROUND: While PM₂.₅ exposure is linked to asthma exacerbations, components-specific effects on healthcare burden remain understudied. Hospital length of stay (LOS), a critical indicator of disease severity and healthcare costs, has received limited attention in black carbon (BC) research. To quantify the association between short-term exposure to PM₂.₅ components-particularly black carbon (BC)-and LOS among asthma patients, and to identify vulnerable populations and critical exposure windows. We conducted a retrospective cohort study of 4,509 asthma patients (ICD-10: J45 ~ J46) hospitalized in Yulin, China (2018 ~ 2023). Daily PM2.5 components concentrations (BC, Organic Matter, Sulfates, Nitrates, Ammonium) were derived from 10-km resolution CMAQ model data. General linear models (GLM) and restricted cubic spline (RCS) assessed exposure-response relationships across lag0-lag10, stratified by age groups and seasons. Confounders included meteorological variables, patient demographics, and clinical characteristics. Each 1.00µg/m³ increase in BC concentration at lag9 significantly associated with a 0.45-days prolongation in hospital stay (95%CI: 0.12 ~ 0.78). Age-stratified analysis revealed heightened vulnerability in children (effect observed at lag1 ~ 3, lag7 ~ 9) and middle-aged adults (sustained effects lag2 ~ 10), while elderly patients showed no significant associations. Seasonal analysis demonstrated that BC effects were more pronounced during non-pollen season (0.77 additional days per 1.00µg/m³ increase), with no significant effects during pollen season. Restricted cubic spline analysis confirmed dose-response relationships, with effects plateauing at BC concentrations ≥ 1.98µg/m³. Short-term BC exposure was significantly associated with extend asthma hospitalization duration, with critical exposure windows at lag9 and pronounced vulnerability in children and middle-aged adults during non-pollen seasons. These findings provide quantitative evidence supporting BC-specific emission controls in air quality policies and highlight the need for targeted protection of vulnerable populations, particularly in high-population regions.

Adequate pollen nutrition plays a crucial role in honey bee development and resilience to stressors. This study investigated the physiological responses of newly emerged Italian honey bee workers (Apis mellifera ligustica Spin.) to pollen diets collected at different times throughout the beekeeping season in a suburban area of Central Italy. The objective was to evaluate how variation in pollen composition and diversity influences key physiological traits and potential resistance to Vairimorpha spp. infection of workers. Corbicular pollen loads were collected every three weeks from March to August, and characterised through palynological, proximate, and mineral analyses. In-cage feeding trials were conducted over two weeks, evaluating daily intake, body composition (crude protein and lipid content), hypopharyngeal gland development, ovary maturation, and Vairimorpha apis and V. ceranae spore loads using RT-PCR and sequencing. Results showed that pollen collected during the central part of the season (April–June) had higher botanical diversity and nutrient content, particularly in proteins and key minerals (Mg, P, Cu, and Zn). Honey bees fed with these pollens exhibited greater development of hypopharyngeal glands, higher protein and lipid body reserves, and reduced relative Vairimorpha spp. spore loads compared to controls. Notably, pollen diets enhanced physiological development even when infection was present, suggesting a buffering effect of high-quality nutrition. These findings confirm the importance of seasonal pollen quality and diversity in sustaining bee health. Future studies should focus on experimental infections and compare mono- versus multifloral diets to better define nutritional strategies for beekeeping under changing environmental conditions.

Abstract Background There is a distinct pattern in pollen dispersal between urban and rural environments, but the pattern of allergen concentration has not been studied so far. Methods We studied the pollen and allergen levels of three important aeroallergens (Betula, Poaceae and Ambrosia) in the urban area of Bratislava and a nearby rural area of Kaplna (Slovakia), their diurnal variation and the influence of meteorological factors during two pollen seasons. Results In the urban area, we found the pollen season more intense regarding both pollen and allergen levels for Betula and Poaceae, possibly due to differences in the distribution of Betula and the spectrum of Poaceae species. A shift towards an earlier peak of diurnal variability of Poaceae pollen was also observed in the urban environment, which is explainable by different microclimatic conditions. However, there was no significant variation in Ambrosia pollen and allergen levels and diurnal variation between the two areas, since this species is widespread and flowers during a period when the microclimatic conditions are more even. Conclusion The findings of this study highlight the need to consider the urban-rural differences and their influence on different plant taxa when assessing public health risks from airborne allergens.

Modelling of airborne birch pollen over Central Europe - model evaluation and sensitivity analysis.

A 15-year survey of pollen aeroallergens in North Texas.