• Paul Schutzmeier, Susanne Kutzora, Isabella Mittermeier, Jana Becker, Karl-Christian Bergmann, Stephan Böse-O’Reilly, Jeroen Buters, Athanasios Damialis, Joachim Heinrich, Michael Kabesch, Hanna Mertes, Dennis Nowak, Christine Korbely, Sandra Walser-Reichenbach, Alisa Weinberger, Stefanie Heinze, Nadine Steckling-Muschack, Caroline Herr. Non-pharmacological interventions for pollen-induced allergic symptoms: Systematic literature review.  https://doi.org/10.1111/pai.13690

First published: 30 October 2021

Abstract: Background: Allergic diseases pose a health problem worldwide. Pollen are widespread aeroallergens which can cause symptoms like shortness of breath, cough, itchy eyes, or rhinitis. Apart from preventive measures and pharmacological treatment, also non-pharmacological interventions have been suggested to reduce symptoms. The objective of this work was to review studies investigating the effectiveness of non-pharmacologic interventions to reduce allergic symptoms.

• Rojo J., Picornell A., Oteros J., Werchan M., Werchan B., Bergmann KC., Smith M., Weichenmeier I., Schmidt-Weber CB., Buters J. (2021) Consequences of climate change on airborne pollen in Bavaria, Central Europe.  Reg Environ Change 2021;21(9) https://doi.org/10.1007/s10113-020-01729-z
  (First published: 08 January 2021)
  Abstract: Climate change affects the reproductive life cycles of plants, including pollen production, which has consequences for allergic respiratory diseases. We examined climatic trends at eight locations in Bavaria, Southern Germany, with pollen time series of at least 10 years (up to 30 years in Munich). Climate change in Bavaria was characterized by a rise in temperature, but not during the winter. There is also a trend towards a more continental climate in Bavaria, which is significant in the Alps in the south of the territory. The influence of climate change depended on pollen type. Wind-pollinated arboreal species (e.g. Alnus, Betula and Cupressaceae/Taxaceae) showed advances in the start and end dates of pollen seasons and an increase in pollen load. These changes correlated negatively with late-winter (February) and spring temperatures (April). For herbaceous species, like Poaceae and Urticaceae, an earlier season was observed. Although precipitation is not a limiting factor in Southern Germany, water availability in the spring did influence the magnitude of grass pollen seasons. The effect of climatic change on the characteristics of pollen seasons was also more pronounced at higher altitudes, significant at >?800 m above sea level. Our results show that trends for start, end dates and intensity were similar at all locations, but only statistically significant at some. If we assume that earlier and more intense pollen seasons result in increases in prevalence and severity of allergic diseases, then the effect of climate change on public health in Bavaria may be significant.
  

• Bergmann, KC., Klimek, L., Nehr, S., Straff, W., Werchan, B. (2021) Allergenic pollen: is it also an indoor problem?. Allergo J Int (2021). https://doi.org/10.1007/s40629-020-00161-3
  (First published: 28 January 2021)

• Damialis A., Gilles S., Sofiev M., Sofieva V., Kolek F., Bayr D., et al. (2021) Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe. PNAS 2021;118(12) https://doi.org/10.1073/pnas.2019034118 (Available online 08 March 2021)
  Abstract: Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown?no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen?virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.

• Steckling-Muschack N., Mertes H., Mittermeier I., et al. (2021) A systematic review of threshold values of pollen concentrations for symptoms of allergy. Aerobiologia 2021;37(1):1-30. https://doi.org/10.1007/s10453-021-09709-4
  (First published: 28 May 2021)
  Abstract: Pollen threshold values used in public warning systems are intended to inform people of the risk of developing allergy symptoms. However, there is no consensus about which pollen concentrations provoke allergy symptoms. The aim of this systematic review was the evaluation of studies investigating the relationship between pollen concentrations (alder, ash, birch, hazel, mugwort and ragweed) and the number of cases in which participants visited a doctor, drug consumption and allergy symptoms. This systematic literature review is registered in PROSPERO (CRD42019112369). A PubMed search was applied and enriched by consultation with experts and a snowball strategy. The included studies were checked for risk of bias (RoB), and extensive data were extracted and compared. Of 511 studies, 22 were eligible according to the previously established inclusion criteria, and 17 from these showed a low RoB. The strongest evidence was reported for ash (Fraxinus) pollen, where an increase of number of doctor’s visits at an interquartile range (IQR) of 18–28 grains/m3 was detected by three studies. Five studies about birch (Betula) pollen showed a threshold value of 45 grains/m3 for increased drug consumption. The evidence of a threshold value was limited for alder (Alnus), hazel (Corylus), mugwort (Artemisia) and ragweed (Ambrosia) pollen. The inconsistent results concerning all types of pollen, except ash pollen, can be the result of multiple factors, e.g., age, gender, allergen content of pollen and individual sensitivity. These influencing factors should be investigated more closely in future research.

• Becker J., Steckling-Muschack N., Mittermeier I., Bergmann KC., Böse-O’Reilly S., Buters S., Damialis A., Heigl K., Heinrich J., Kabesch M., Mertes H., Nowak D., Schutzmeier P., Walser-Reichenbach S., Weinberger A., Korbely C., Herr C., Heinze S., Kutzora S. (2021) Threshold values of grass pollen (Poaceae) concentrations and increase in emergency department visits, hospital admissions, drug consumption and allergic symptoms in patients with allergic rhinitis: a systematic review. Aerobiologia 2021;37(4):633-62. https://doi.org/10.1007/s10453-021-09720-9
  (First published: 19 July 2021)
  Abstract: Airborne grass (Poaceae) pollen measurements are used in public warning systems to inform people about the risk of allergic symptoms. However, there is no consensus about which exact thresholds of pollen concentrations provoke the allergic symptoms. The aim of this study was to review the relevant scientific information on the relationship between grass pollen concentrations and the occurrence of emergency department (ED) visits, hospital admissions (HA), drug consumption and allergic symptoms. Literature search was conducted by experts’ consultation and snowball strategy. Studies meeting the criteria for inclusion were assessed regarding their risk of bias (RoB). A high RoB resulted in exclusion of the study from data synthesis. Extensive data were extracted and qualitatively compared. The review is registered in PROSPERO. 32 Studies were eligible while 18 showed a low RoB and were qualitatively synthesised. Emergency department visits and hospital admissions were mostly investigated. Threshold values of 10 grains/m3 and 12 grains/m3 were reported for ED visits and HA. Evidence exists that an increase of 10 grains/m3 of air leads to a significant increase in adverse health outcomes. Especially at a three-day lag, adverse health effects were shown. Variations in exposure and outcome measurement make the definition of pollen thresholds difficult. As a consequence, no defined pollen threshold values could be identified. Studies with uniform exposure measures and statistical methods are necessary to gain a better understanding of the impact of grass pollen on human health. Determining personal thresholds could be beneficial for affected people.

• Rojo J., Oteros J., Picornell A., Maya-Manzano JM., Damialis A., Zink K., Werchan M., Werchan B., Smith M., Menzel A., Timpf S., Traidl-Hoffmann C., Bergmann KC., Schmidt-Weber CB., Buters J. (2021) Effects of future climate change on birch abundance and their pollen load.  Glob Chang Biol. 2021;27(22):5934-49. https://doi.org/10.1111/gcb.15824
  (First published: 06 August 2021)
  Abstract: Climate change impacts on the structure and function of ecosystems will worsen public health issues like allergic diseases. Birch trees (Betula spp.) are important sources of aeroallergens in Central and Northern Europe. Birches are vulnerable to climate change as these trees are sensitive to increased temperatures and summer droughts. This study aims to examine the effect of climate change on airborne birch pollen concentrations in Central Europe using Bavaria in Southern Germany as a case study. Pollen data from 28 monitoring stations in Bavaria were used in this study, with time series of up 30 years long. An integrative approach was used to model airborne birch pollen concentrations taking into account drivers influencing birch tree abundance and birch pollen production and projections made according to different climate change and socioeconomic scenarios. Birch tree abundance is projected to decrease in parts of Bavaria at different rates, depending on the climate scenario, particularly in current centres of the species distribution. Climate change is expected to result in initial increases in pollen load but, due to the reduction in birch trees, the amount of airborne birch pollen will decrease at lower altitudes. Conversely, higher altitude areas will experience expansions in birch tree distribution and subsequent increases in airborne birch pollen in the future. Even considering restrictions for migration rates, increases in pollen load are likely in Southwestern areas, where positive trends have already been detected during the last three decades. Integrating models for the distribution and abundance of pollen sources and the drivers that control birch pollen production allowed us to model airborne birch pollen concentrations in the future. The magnitude of changes depends on location and climate change scenario.

• Sandra Linngrön, Julia Scheumann, Barbora Werchan, Daniel Wildner, Thomas Heilmann, Karl-Christian Bergmann (2021) Die „Husteblume“ der Techniker-Krankenkasse: erste evaluierte App für Patienten mit allergischer Rhinokonjunktivitis und allergischem Asthma durch Pollen. Allergo J. 2021;30(6):45-8 https://doi.org/10.1007/s15007-021-4864-z
  Zusammenfassung: Die App „Husteblume“ der Techniker Krankenkasse (TK) Hamburg bietet Personen mit einer Pollenallergie (allergische Rhinokonjunktivitis und Pollenasthma) die Möglichkeit einer verbesserten Selbstkontrolle der Erkrankung durch eine Pollenflugvorhersage, Dokumentations-möglichkeiten für das Gesamtbefinden und der nasalen, konjunktivalen und bronchialen Symptome, der benutzten Medikation sowie eine Patienteninformation mit Vorschlägen zur Therapie, Lexikon, Mediathek und Pollenflugkalender. In zwei Online-Umfragen unter registrierten Nutzern der App vor und nach der Pollensaison 2017 wurden Benutzerfreundlichkeit, Veränderungen der Lebensqualität, der Gesundheitskompetenz und der Selbstwirksamkeit bei der Behandlung evaluiert. Die Ergebnisse waren positiv und verdeutlichen, dass gut umgesetzte Apps einen positiven Beitrag zum Selbstmanagement leisten können.

• (A) Bergmann KC., Berger M., Klimek L., Pfaar O., Werchan B., Werchan M., Zuberbier T. (2021) Nonpharmacological measures to prevent allergic symptoms in pollen allergy: A critical review.  Allergologie select 2021;5(1):349-60. https://doi.org/10.5414/ALX02294E
  (First published: 01 December 2021)
  Abstract: Allergic rhinoconjunctivitis (hay fever) is the most common chronic disease in all industrialized nations. Therapy consists essentially in the use of anti-allergic and anti-inflammatory drugs, which mostly show a good and quick effect. With allergenspecific immunotherapy, there is also a causal possibility of tolerance induction. There is currently a considerable undersupply, as those affected trivialize the symptoms and often have concerns about long-term drug therapy. There is also great interest in using non-medicinal measures to prevent and/or relieve allergic symptoms on the assumption that these are free from side effects. In this publication, we present non-drug methods for which clinical studies are available in the literature. The methods have varying degrees of effectiveness. An evidence-based comparative assessment between the methods is not possible. There are also hardly any studies in comparison to standard drug therapy. A large number of the interventions consist of allergen reduction, e.g., with air filters, or cleaning of the mucous membranes with nasal irrigation, etc., none of which should be seen as a substitute but as a supplement to drug therapy.

• (B) Bergmann KC., Berger M., Klimek L., Pfaar O., Werchan B., Werchan M., Zuberbier T. (2021) Nicht medikamentöse Maßnahmen zur Vermeidung allergischer Symptome bei der Pollenallergie – eine kritische Übersicht. Allergologie 2021;44(12):943-56. DOI 10.5414/ALX02294
  Zusammenfassung: Die allergische Rhinokonjunktivitis (Heuschnupfen) ist die häufigste chronische Erkrankung in allen Industrienationen. Ihre Therapie besteht im Wesentlichen in der Anwendung anti-allergischer und anti-entzündlicher Medikamente, die zumeist einen guten und schnellen Effekt zeigen. Mit der allergenspezifischen Immuntherapie besteht darüber hinaus eine kausale Möglichkeit der Toleranzinduktion. Gegenwärtig besteht eine erhebliche Unterversorgung, da Betroffene die Symptome trivialisieren und öfter auch Bedenken gegen eine medikamentöse Dauertherapie haben. Es besteht ein hohes Interesse, auch nicht medikamentöse Maßnahmen zur Vorbeugung und/oder Linderung der allergischen Symptome zu verwenden in der Annahme, dass diese frei von Nebenwirkungen zu seien. In dieser Publikation stellen wir nicht medikamentöse Methoden vor, zu denen klinische Studien in der Literatur vorliegen. Die Methoden haben eine unterschiedlich gute Wirksamkeit. Eine evidenzbasierte vergleichende Einschätzung zwischen den Methoden ist nicht möglich. Ebenfalls liegen kaum Studien im Vergleich zur medikamentösen Standardtherapie vor. Eine Vielzahl der Interventionen besteht in einer Allergenreduktion, wie zum Beispiel durch Luftfilter, oder einer Reinigung der Schleimhäute durch Nasenspülungen etc., die allesamt keinesfalls als Ersatz, sondern als Ergänzung zur medikamentösen Therapie gesehen werden sollten.

• B. Werchan, M. Werchan, S. Röseler, K.-C. Bergmann. (2021) Die Wochenpollenvorhersage der Stiftung Deutscher Polleninformationsdienst (PID) – ein Hilfsmittel für Pollenallergiker und deren behandelnde Ärzte in Deutschland. Allergologie 2021;44(12):920-926. DOI 10.5414/ALX02295
  Zusammenfassung: In Deutschland leidet fast jeder siebte Erwachsene an medizinisch diagnostizierter allergischer Rhinitis, die häufig durch eine Reaktion auf Pollen verursacht wird. Wie in anderen europäischen Ländern gibt es auch in Deutschland ein nationales Pollenmessnetz (Stiftung Deutscher Polleninformationsdienst (PID)), das die Pollen- und Pilzsporenkonzentrationen in der Außenluft überwacht und Allergiker und Ärzte informiert. Eines der Informationsinstrumente des PID ist seit dem Jahr 2016 die Wochenpollenvorhersage des PID für Deutschland. Diese wird auf der Grundlage von real gemessenen Pollendaten, phänologischen Beobachtungen, Wettervorhersagen und Fachwissen u. a. in Aerobiologie, Botanik und Allergologie erstellt. Die Vorhersage informiert während der gesamten Pollenflugzeit über den aktuellen Stand und die Entwicklung des Aufkommens von insgesamt rund 50 Pollenarten und vier Pilzsporengattungen für einen Prognosezeitraum von 7 Tagen.