Increasing Awareness Regarding the Relationship between Environmental Exposures and Allergic Disease.

This review highlights studies from the past 3 years that add to the understanding of the impact of environmental exposures on allergic disease. These include aeroallergens, air quality, prenatal or early life exposures, and occupational exposures. Recent studies focused on the relationship between the environment, the microbiome, and allergic disease as well as new therapeutic options are also reviewed. Lastly, there has been significant recent research that improves our knowledge of the link between health disparities and environmental exposures. These scientific advances have resulted in a better understanding that sets the foundation for current and future research dedicated to improving health outcomes by modifying environmental exposures.

Polysensitisation is associated with more severe symptoms: The reality of patients with allergy.

BACKGROUND: Studying the sensitisation profiles of patients with allergies allows for a deeper understanding of the disease which may facilitate the selection of the best-personalised allergen immunotherapy. This observational, cross-sectional, multicentre study aimed to demonstrate the heterogeneity of the German population with allergies by analysing specific immunoglobulin E (sIgE) patterns towards aeroallergens and exploring the relationship between sensitisation and clinical symptoms. METHODS: In total, 500 patients with allergies from different regions of Germany were recruited based on their case histories, clinical allergic symptoms and skin prick test data for aeroallergens. Serum samples were analysed using ImmunoCAP assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens. RESULTS: Most patients (81%) were polysensitised. Betula verrucosa pollen was the most common cause of sensitisation (59%), followed by Phleum pratense (58%) and Dermatophagoides pteronyssinus (44%). The highest prevalence rates of molecular allergens were observed for Bet v 1 (84%) from birch pollen, Phl p 1 from grass pollen (82%), Der p 2 (69%) from mites and Fel d 1 (69%) from cat. Polysensitisation was significantly associated with the presence of asthma and the severity of rhinitis symptoms. CONCLUSIONS: Our findings show a high rate of polysensitisation and emphasise the importance of molecular diagnosis for more precise and comprehensive insights into sensitisation patterns and their association with clinical symptoms. These data may help improve personalised diagnosis and immunotherapy adapted to the needs of individual patients in the region.

Bioaerosol Exposures and Respiratory Diseases in Cannabis Workers.

PURPOSE OF REVIEW: This review investigates occupational inhalation hazards associated with biologically derived airborne particles (bioaerosols) generated in indoor cannabis cultivation and manufacturing facilities. RECENT FINDINGS: Indoor cannabis production is growing across the US as are recent reports of respiratory diseases among cannabis workers, including occupational asthma morbidity and mortality. More information is needed to understand how bioaerosol exposure in cannabis facilities impacts worker health and occupational disease risk. Preliminary studies demonstrate a significant fraction of airborne particles in cannabis facilities are comprised of fungal spores, bacteria, and plant material, which may also contain hazardous microbial metabolites and allergens. These bioaerosols may pose pathogenic, allergenic, toxigenic, and pro-inflammatory risks to workers. The absence of multi-level, holistic bioaerosol research in cannabis work environments necessitates further characterization of the potential respiratory hazards and effective risk prevention methods to safeguard occupational health as the cannabis industry continues to expand across the US and beyond.

Meteorological factors and climate change impact on asthma: a systematic review of epidemiological evidence.

OBJECTIVE: This systematic review aimed to investigate the epidemiological data about meteorological factors and climate change (CC) impact on asthma. DATA SOURCES: A search was performed using three databases (Web of Science, Science Direct, and MEDLINE) for all relevant studies published from January 1, 2018, to December 31, 2022. STUDY SELECTIONS: This systematic review complied with the PRISMA document's requirements, including studies related to meteorological factors and CC impact on asthma. The search included studies published in English or French language, and was based on title, abstract, and complete text. Documents not meeting inclusion requirements were excluded. RESULTS: We identified 18 studies published in the last five years that were eligible for inclusion in this review. We found that these studies concerned European, Asian, American, and Oceanic cities. Extreme variations in temperature, humidity, wind speed, exceptional incidents like hurricanes, cold and heat waves, and seasonal shifts were strongly correlated with the worsening of asthmatic symptoms, particularly in childhood. In addition, excessive concentrations of air pollutants and aeroallergens were linked to pediatric asthma emergency hospital admissions. CONCLUSIONS: A significant association between the consequences of CC and asthma in adults particularly in children has been demonstrated. Future research should quantify the impact of global change in climate regarding the aeroallergens' distribution in terms of geography and time. It is also necessary to research the impact of air pollution on asthmatic health, like sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and particles having an aerodynamic diameter lower than 2.5 µm (PM2.5).

Clonal evolution and stereotyped sequences of human IgE lineages in aeroallergen-specific immunotherapy.

BACKGROUND: Allergic disease reflects specific inflammatory processes initiated by interaction between allergen and allergen-specific IgE. Specific immunotherapy (SIT) is an effective long-term treatment option, but the mechanisms by which SIT provides desensitization are not well understood. OBJECTIVE: Our aim was to characterize IgE sequences expressed by allergen-specific B cells over a 3-year longitudinal study of patients with aeroallergies who were undergoing SIT. METHODS: Allergen-specific IgE-expressing clones were identified by using combinatorial single-chain variable fragment libraries and tracked in PBMCs and nasal biopsy samples over a 3-year period with antibody gene repertoire sequencing. The characteristics of private IgE-expressing clones were compared with those of stereotyped or "public" IgE responses to the grass pollen allergen Phleum pratense (Phl p) 2. RESULT: Members of the same allergen-specific IgE lineages were observed in nasal biopsy samples and blood, and lineages detected at baseline persisted in blood and nasal biopsy samples after 3 years of SIT, including B cells that express IgE. Evidence of progressive class switch recombination to IgG subclasses was observed after 3 years of SIT. A common stereotyped Phl p 2-specific antibody heavy chain sequence was detected in multiple donors. The amino acid residues enriched in IgE-stereotyped sequences from seropositive donors were analyzed with machine learning and k-mer motif discovery. Stereotyped IgE sequences had lower overall rates of somatic hypermutation and antigen selection than did single-chain variable fragment-derived allergen-specific sequences or IgE sequences of unknown specificity. CONCLUSION: Longitudinal tracking of rare circulating and tissue-resident allergen-specific IgE+ clones demonstrates persistence of allergen-specific IgE+ clones, progressive class switch recombination to IgG subtypes, and distinct maturation of a stereotyped Phl p 2 clonotype.

Do respiratory virus infections modify associations of asthma exacerbation with aeroallergens or fine particulate matter? A time series study in Philadelphia PA.

Respiratory virus infections are related to over 80% of childhood asthma exacerbations. They enhance pro-inflammatory mediator release, especially for sensitized individuals exposed to pollens/molds. Using a time-series study design, we investigated possible effect modification by respiratory virus infections of the associations between aeroallergens/PM2.5 and asthma exacerbation rates. Outpatient, emergency department (ED), and inpatient visits for asthma exacerbation among children with asthma (28,540/24,444 [warm/cold season]), as well as viral infection counts were obtained from electronic health records of the Children's Hospital of Philadelphia from 2011 to 2016. Rate ratios (RRs, 90th percentile vs. 0) for late-season grass pollen were 1.00 (0.85-1.17), 1.04 (0.95-1.15), and 1.12 (0.96-1.32), respectively, for respiratory syncytial virus (RSV) counts within each tertile. However, similar trends were not observed for weed pollens/molds or PM2.5. Overall, our study provides little evidence supporting effect modification by respiratory viral infections.

Efficacy of tezepelumab in patients with evidence of severe allergic asthma: Results from the phase 3 NAVIGATOR study.

BACKGROUND: Allergic asthma is the most common phenotype among patients with severe asthma. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) versus placebo in patients with severe, uncontrolled asthma. This exploratory analysis evaluated the efficacy of tezepelumab in NAVIGATOR participants with evidence of severe allergic asthma. METHODS: Patients (12-80 years old) receiving medium- or high-dose inhaled corticosteroids and ≥ 1 additional controller medication, with or without oral corticosteroids, were randomized to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks in NAVIGATOR. In this analysis, the AAER, forced expiratory volume in 1 second (FEV1 ), patient-reported outcomes (PROs), and type 2 biomarker levels were evaluated in patients grouped by sensitivity to perennial aeroallergens, confirmed symptomatic allergy, and eligibility for omalizumab treatment according to the United States (OMA-US) and the European Union (OMA-EU) prescribing information, including subgroups according to baseline blood eosinophil counts and fractional exhaled nitric oxide (FeNO) levels. RESULTS: Of 1059 patients who received treatment in NAVIGATOR, 680 (64%) had perennial aeroallergen sensitivity and 318 (30%) had confirmed symptomatic allergy; 379 (36%) and 359 (34%) patients were OMA-US- and OMA-EU-eligible, respectively. Tezepelumab reduced the AAER over 52 weeks versus placebo by 58% (95% confidence interval [CI]: 47-67) to 68% (95% CI: 55-77) across these subgroups. Among omalizumab-eligible patients, AAERs were reduced in patients across baseline blood eosinophil counts and FeNO levels. Tezepelumab improved FEV1 and PROs, and reduced type 2 biomarkers, versus placebo in patients with and without perennial allergy. CONCLUSIONS: Tezepelumab was efficacious in patients with severe, uncontrolled asthma with evidence of allergic inflammation, defined by multiple clinically relevant definitions. These findings further support the benefits of tezepelumab in a broad population of patients with severe asthma, including those with severe allergic asthma.

Prevalence of common sensitizing aeroallergens in patients with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD), a skin disease burden worldwide, is a complex, multifactorial, chronic inflammatory disease. Prevalence of AD is increasing in developing countries and identifying the causative allergens is a major challenge. Aeroallergens are shown to aggravate atopic dermatitis. PURPOSE: Explore the prevalence of aeroallergens sensitization in patients with AD and its possible relation with AD severity. METHODS: Cross-sectional study of 132 patients diagnosed to have atopic dermatitis. Atopy was detected by serum specific IgE to a panel of the most encountered aeroallergens. RESULTS: From the 132 patients, elevated specific IgE was detected in 72.7 % from which 59.1 % were mild and 86.4 % are moderate/severe as well as 15.9 % are mono-sensitized and 54.5 % are poly-sensitized with poly-sensitization being more in severe cases compared to mild cases (68.2 % vs 4.5 %). Regarding specific IgE to different aeroallergens, the most prevalent were Dermatophagoides pteronyssinus (50 %), followed by Dermatophagoides farinae (34.1 %), Birch pollen (20.5 %), cat epithelium (18.2 %) Regweed (15.9 %), and Cockroach (9.1 %). However, moderate to severe cases were more sensitized to candida (p = 0.012), mix grass pollen (p = 0.002), ragweed (0.00), mite (p = 0.037) and cat epithelium (p = 0.007). CONCLUSION: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Birch pollen, cat epithelium Regweed and Cockroach are the most frequent sensitizing aeroallergens in atopic dermatitis.

Air Sampling and Analysis of Aeroallergens: Current and Future Approaches.

PURPOSE OF REVIEW: To review current air sampling instruments and analysis methods and to describe new approaches being developed. RECENT FINDINGS: Spore trap sampling with analysis by microscopy remains the most widely used methods for aeroallergen determination even though there are often long delays from sample acquisition to data availability, as well as a need for specially-trained staff for sample analysis. The use of immunoassays and molecular biology to analyze outdoor or indoor samples has expanded in recent years and has provided valuable data on allergen exposure. New automated sampling devices capture pollen, analyze, and identify pollen grains by light scattering, laser-induced fluorescence, microscopy, or holography using signal or image processing to classify the pollen in real time or near real time. Air sampling data from current methods provide valuable information on aeroallergen exposure. The automated devices in use and under development show great potential but are not ready to replace existing aeroallergen networks.

Development, validation and application of a questionnaire to qualify the indoor environmental exposure of patients with respiratory allergy.

OBJECTIVE: Environmental control includes measures to prevent exposure to common aeroallergens in an individual's home. Questionnaires are part of the clinical practice of health assessment, and are also widely used in research. Our aim was to develop and validate a questionnaire to identify possible sources of aeroallergens present in the indoor environment. METHODS: This study describes the development, validation and application of a questionnaire. For content validation the Content Validation Index and Ordinal Cronbach's Alpha Index have been used; Polychoric Correlations for the agreement between judges; and an Exploratory Factor Analysis for the structure of the questionnaire, while for reliability assessment, Intraclass Correlation Coefficient has been applied. RESULTS: Twenty-one doctors participated as judges to validate the questionnaire, which 204 patients answered. The Content Validity Index for all the questions on the "Clarity" aspect was 0.846 ± 0.152 and on the "Relevance" aspect, 0.954 ± 0.080. Cronbach's alpha coefficient for the "Clarity" aspect was 0.88 with a 95% confidence intervals (CI) and the "Relevance" aspect, 0.94 with a 95% CI. The average Intraclass Correlation Coefficient was 0.94 and all the F tests were highly significant. CONCLUSIONS: The questionnaire developed by our group was considered valid and reliable, and is capable of portraying the home environment without the need for a personal visit to the patient's home. This questionnaire would be a good tool to use in research or during patient consultations to assess the patient's home environment, as this latter assessment is essential for the management of patients with respiratory allergies.

Aeroallergen sensitization in school-age children with allergic rhinitis: What has changed during the COVID-19 pandemic?

BACKGROUND: Pandemic period may affect aeroallergen sensitization. OBJECTIVE: The study aimed to investigate changes in allergen sensitivities of skin prick test (SPT) in patients with allergic rhinitis (AR) during pandemic and to evaluate relationship with disease severity. METHODS: In all, 164 AR patients with or without asthma, aged 6-17 years, who have undergone SPTs prior to the pandemic and after October 1, 2021 (18th month of the pandemic), were evaluated retrospectively. The wheal size of allergens in performed SPTs during and prior to the pandemic were compared. Detected changes in allergen sensitivities via SPT results were compared with changes in the disease severity parameters (AR severity, asthma severity, and the number of asthma exacerbations per year), frequency of upper respiratory tract infections and antibiotic use, laboratory parameters, demographic characteristics, and visual analogue scores (VAS). RESULTS: House dust mites (HDMs), cat, pollen, Artemisia, and Cupressus sensitization increased in AR patients during the Coronavirus disease 2019 (COVID-19) pandemic. HDM, mold, and pollen wheal diameters increased in SPTs. Proportion of polysensitization increased during the pandemic, compared to pre-pandemic period (9.1% vs 3%; P < 0.001), and number of non-sensitized patients decreased during the pandemic period compared to the pre-pandemic period (7.9% vs 22.6%; P < 0.001). An increase in HDM sensitivity in SPTs was correlated with VAS for nasal blockage, and an increase in cat sensitivity was correlated with VAS for all nasal symptoms. CONCLUSION: We believe that inhalant allergen sensitization might have been affected by the lifestyle changes of patients during the pandemic. Hence, it is important to evaluate patients for allergen sensitization, especially patients with moderate/severe AR, to revise disease control measurements.

Clinical efficacy and safety of coseasonal initiation of Artemisia annua sublingual immunotherapy on patients with Artemisia-induced rhinoconjunctivitis.

PURPOSE: Patients with seasonal allergic rhinoconjunctivitis (SARC) might seek evaluation and treatment when symptoms appear during the pollen season. It is unclear whether coseasonal-initiated sublingual immunotherapy (SLIT) would be effective and safe for SARC. This study aims to identify the feasibility of initiating Artemisia annua SLIT during the pollen season. MATERIALS AND METHODS: Sixty patients with Artemisia-induced SARC were equally recruited into the SLIT and control groups during the pollen season in 2021. The SLIT group was treated with standardized Artemisia annua SLIT drops using a modified dosing schedule combined with pharmacotherapy, while the control group only received pharmacotherapy. Diary cards for clinical symptoms, rescue medication use, and adverse events (AEs) were recorded during the pollen seasons. Objective measures, including average daily combined scores of medication and rhinoconjunctivitis symptoms (CSMRS), total rhinoconjunctivitis symptom score (TRSS), total medication score (TMS), and the score of visual analog scale (VAS) were calculated to evaluate the efficacy of SLIT. Safety was assessed through the occurrence and severity of AEs. RESULTS: In total, 80.0 % (24/30) patients in the SLIT group and 86.67 % (26/30) patients in the control group completed the study. The severity of SARC, which was assessed by objective measures including CSMRS, TRSS, TMS, and VAS of the SLIT group and the control group, was generally at the same level during the 2021 pollen season, except for the medical consumption, which the score of TMS was slightly higher in the SLIT group. After one year of treatment, the scores of CSMRS, TRSS, and VAS in the SLIT group were significantly improved compared with the control group (all P < 0.001), and the difference in the TMS between the two groups disappeared (P > 0.05). Moreover, clinical improvement of the four objective measures was also observed in the SLIT group compared with the baseline value (P < 0.001). Overall, 9/24 patients in the SLIT group experienced mild local AEs, and two patients experienced mild systemic AEs during the SLIT period. CONCLUSIONS: This controlled preliminary study identified that coseasonal-initiated Artemisia annua SLIT treatment for one year was generally safe and effective in improving the symptoms of SARC patients induced by Artemisia annua pollen.

Eosinophilic Esophagitis due to Aeroallergens: A Systematic Review and Update.

Eosinophilic esophagitis is a chronic antigen-mediated esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by TH2 inflammation (at least 15 eosinophils/high power field) when other secondary systemic and local causes of esophageal eosinophilia are excluded. Although this disease was initially ascribed to a delayed reaction to food allergens, emerging evidence suggests that aeroallergens may also play a role in pathogenesis and disease course. Some studies support seasonal variations in the diagnosis of eosinophilic esophagitis and disease exacerbations owing to the increase in aeroallergens to which patients are sensitized. It is also known that this disease can be caused by extensive, identifiable exposure to aeroallergens and after treatment with specific immunotherapy based on food or aeroallergens. It was recently postulated that treatment of allergic rhinoconjunctivitis can improve the symptoms of eosinophilic esophagitis, although data are limited to case reports and small series. Currently, biomarkers and biologic therapies are not helpful for diagnosis or inducing clinical and histological remission of the disease. Nevertheless, there are high hopes for dupilumab. This review aims to give visibility to the involvement of aeroallergens in the triggering and exacerbation of eosinophilic esophagitis, since many of them, in addition to being airborne and inhalant, can also be ingested as food. Clearly, we must try to identify the cause of the disease to ensure remission.

Allergic vulvovaginitis: a systematic literature review.

PURPOSE: Despite the vaginal mucosa is able to respond to allergenic stimuli, vaginal allergic responses have been under investigated in clinical practice. Thus, we aimed to identify the most frequent etiological agents responsible for vulvovaginal allergies, the prevalent signs/symptoms, and the diagnostic tests applied in this clinical condition. METHODS: Literature search was performed on PubMed, Scopus, Scielo, Web of Science, and EMBASE. The study protocol was registered on PROSPERO (CRD42020167238). Studies were divided in two groups depending on allergen exposure route. Due to a significant number of studies correlating allergy to Candida infection, subgroup analysis was included. RESULTS: In direct exposure cases, Human Seminal Plasma was the most prevalent allergen, sensitizing 73% of affected women. These women presented localized swelling and burning as prevalent symptoms, affecting 42/68 and 36/68 women, respectively. Cutaneous Prick tests were applied in 58/68 women, either alone or combined with IgE measurements. Regarding cases of indirect/unidentified exposure, house dust mites was the most prevalent allergen (54%), followed by pollen (44%). Predominant symptoms were vulvar pruritus and burning, affecting 67/98 and 52/98 women. Skin prick test was the most prevalent diagnostic method used among different studies. Hypersensitivity toward Candida antigen was present in only half (163/323) of women presenting concomitant allergy and Candida infection. CONCLUSION: From the two types of allergen exposure that can cause vulvovaginal allergic responses, direct contact of the antigen with the vulva and/or vagina was the most prevalent. Still, allergens can also sensitize the vaginal mucosa secondarily to other exposure route, specifically aeroallergens.

Pattern of skin sensitivity to various aeroallergens by skin prick test in patients of allergic airway disease in South Western Maharashtra.

Background: The prevalence of allergic diseases such as asthma and allergic rhinitis is high in the general population, and aeroallergens are the most common allergens that cause airway inflammation. Skin prick testing (SPT) is a validated method to diagnose IgE-mediated allergic diseases. The knowledge of allergen sensitivity pattern in this part of India is limited. The present study was undertaken to identify common aeroallergens prevalent in this area using a standardized SPT. Methods: We did a cross-sectional hospital-based study. A total of 330 patients of proven allergic airway disease underwent SPT. We used a validated skin prick test which included 22 allergen extracts, 1 positive control, and 1 negative control. Results: A total of 327 patients were included in the study. Two hundred seventy-one (82.27%, n = 327) patients had a positive SPT to one or more aeroallergen extract. The sensitivity of Dermatophagoides pteronyssinus (49.85%) was seen in the maximum number of people followed by Dermatophagoides farinae (47.70%). Conclusions: In our study, dust mites were the most common aeroallergen seen in maximum study subjects.

Investigating the association of atopy and aeroallergen sensitization and chronic spontaneous urticaria.

Introduction: Chronic spontaneous urticaria (CSU) is a common skin allergic reaction with an unknown mechanism. There is inadequate evidence to support the role of aeroallergen sensitization in CSU. Aim: The present study was conducted to investigate the association between the aeroallergen sensitivity and CSU. Material and methods: In this cross-sectional study, 91 patients with CSU were recruited. Information on demographic characteristics was collected. The skin prick test (SPT) for most prevalent aeroallergens and pulmonary function test (PFT) were performed and the results were clinically matched to investigate the allergic rhinitis (AR) and asthma. Total serum immunoglobulin E (IgE) concentration was analysed in the subjects for the presence of atopy. Results: Ninety one patients (75 of them were females) were enrolled in the study (with a mean age of 36.90 ±12.93 years). SPT result was positive in 75 (82.4%) subjects. Weeds (67 cases, 73.6%), trees (61 cases, 67%), and dust mites (55 cases, 60.4%) were the most common pollens in the positive SPT samples. Thirty-seven (40.7%) of the patients had allergic rhinitis. There was a statistically significant association between the presence of AR and positive SPT result (p = 0.002). Eight patients had allergic asthma and 45 (49.4%) of the patients had a total serum IgE level of more than 100 IU/ml. Conclusions: Our results indicated a clear association between the presence of aeroallergen sensitivity and development of CSU. AR exists as a co-morbidity of CSU.

Do we need aerobiological air monitoring in desert climates? The Qatar experience.

Knowledge about diurnal, seasonal, and annual fluctuations in airborne pollen and fungal spores in any geographical area is essential for effective diagnosis and treatment of allergies. Aerobiological analysis enables the detection of airborne pollen and spores, thus providing information on plant phenology, plant distribution, related diseases, and the risks for some species in terms of allergies. Although pollen and fungal spores have been widely studied as aeroallergens throughout the world, not much is known about the biological aerosols in countries with a desert environment; and these could be present in much higher concentrations than expected. Arid desert regions (including the region surrounding the Arab Gulf), characterized by hot weather, poor soils, and low biological productivity, have typically been neglected when building ambitious biomonitoring networks for the large-scale monitoring of biological particles; however, few studies in Kuwait, Saudi Arabia, and recently Qatar have aimed to delineate the various botanical families that contribute to inhalant allergens in this region. Understanding the aerobiological features of countries with hot and desert climates may better prepare healthcare providers to assist patients with allergic rhinitis. It may be argued that one of the reasons why aerobiologists have only recently turned their attention to the state of Qatar investigating how pollen and fungal spore records could contribute to evaluating the correlation between different pollen conditions and allergy symptoms. The first aerobiological network of Qatar was monitoring (2017-2020) the atmospheric pollen concentrations of Doha and Al Khor to determine the association between the possible risk of respiratory allergies and the distribution of certain species throughout the region. In the Qatari database, more than 25 native taxa have been recorded, up to 50% of which can be considered allergenic. This includes Amaranthaceae and Poaceae pollen among the major aeroallergens causing allergy symptoms in Qatar. Our study has confirmed a statistically significant association between Amaranthaceae and asthma and allergic rhinitis. To summarize, it is worth considering aerobiological monitoring in desert climate regions when assessing the effectiveness of pollen allergy therapy and planning prevention methods for patients.

Monitoring techniques for pollen allergy risk assessment.

Understanding airborne pollen allergens trends is of great importance for the high prevalence and the socio-economic impact that pollen-related respiratory diseases have on a global scale. Pursuing this aim, aeropalynology evolved as a broad and complex field, that requires multidisciplinary knowledge covering the molecular identity of pollen allergens, the nature of allergen-bearing particles (pollen grains, pollen sub-particles, and small airborne particles), and the distribution of their sources. To estimate the health hazard that urban vegetation and atmospheric pollen concentrations pose to allergic subjects, it is pivotal to develop efficient and rapid monitoring systems and reliable allergic risk indices. Here, we review different pollen allergens monitoring approaches, classifying them into I) vegetation-based, II) pollen-based, and III) allergen-based, and underlining their advantages and limits. Finally, we discuss the outstanding issues and directions for future research that will further clarify our understanding of pollen aeroallergens dynamics and allergen avoidance strategies.

Pollen forecasting and its relevance in pollen allergen avoidance.

Pollinosis and allergic asthma are respiratory diseases of global relevance, heavily affecting the quality of life of allergic subjects. Since there is not a decisive cure yet, pollen allergic subjects need to avoid exposure to high pollen allergens concentrations. For this purpose, pollen forecasting is an essential tool that needs to be reliable and easily accessible. While forecasting methods are rapidly evolving towards more complex statistical and physical models, the use of simple and traditional methods is still preferred in routine predictions. In this review, we summarise and explain the main parameters considered when forecasting pollen, and classify the different forecasting methods in two groups: observation-based and process-based. Finally, we compare these approaches based on their usefulness to allergic patients, and discuss possible future developments of the field.

Airborne Food Allergen and Aeroallergen Levels in Health Care Settings: An Unaccounted for but Potentially Relevant Source of Exposure?

BACKGROUND AND OBJECTIVE: Exposure to airborne allergens of biological origin is associated with the development and exacerbation of allergic asthma and rhinitis. Assessment of allergen exposure in health care facilities may improve monitoring of hygiene and surveillance of specific allergens that can cause symptoms in sensitized persons. Objective: To assess concentrations of airborne food and aeroallergens in various health care settings in Portugal. METHODS: Dust was vacuumed from primary health care centers in Lisbon and from the emergency department, day hospital, internal medicine ward, operating room, and outpatient clinic of a university central hospital in Porto. Samples were sieved, weighed, and extracted, and concentrations of Nbos d 5, Cor a 9, Gal d 2, Ara h 3, Ara h 6, Der p 1, Fel d 1, Can f 1, Bla g 2, Alt a 1, and Phl p 5 were determined using a multiplex array for allergens (MARIA). RESULTS: All airborne food and aeroallergens were found in at least 1 sampled area, except for Alt a 1. Levels of Der p 1 and Fel d 1 ranged from 13.0 µg/g to 971.0 µg/g and from 7.0 µg/g to 4618.8 µg/g, respectively. Higher levels of food allergens were found in the emergency department (Nbos d 5, 16 034.0 µg/g; and Cor a 9, 10 649.5 µg/g). CONCLUSIONS: Except for the operating room, exposure levels for dust mite and cat and dog dander in health care facilities were above the values associated with sensitization and allergic asthma or rhinitis symptoms in sensitized persons.