A nasally applied cellulose powder in seasonal allergic rhinitis in adults with grass pollen allergy: a double-blind, randomized, placebo-controlled, parallel-group study.

BACKGROUND: A nasally applied cellulose powder is increasingly used in many countries as a remedy for allergic rhinitis. In 2009, a 4-week study in birch pollen-allergic children showed a reduction in nasal symptoms. The best effect occurred on days with lower pollen counts. The present study in grass pollen-allergic adults used the same basic design. METHODS: In May 2013, a double-blind, placebo-controlled study was conducted in 108 patients with allergic rhinitis due to grass pollen (18-40 years of age). SMS on mobile phones were used as reminders of treatment and reporting of symptom scores. RESULTS: We found significant reductions in severity scores for sneezing, runny nose, stuffy nose and symptoms from eyes and lower airways, both separately and together (all p < 0.001). Reflective opinion of effect and guess on treatment at follow-up visits (both p < 0.001) confirmed a high efficacy. No clinically significant adverse effects were reported. CONCLUSIONS: The product provided significant protection against all seasonal allergic rhinitis symptoms from both upper and lower airways during the grass pollen season in an adult population. The magnitude and scope of efficacy support the use of the product as an early choice in the treatment of allergic rhinitis.

Not just a spring fever... Information and advice to help families with hay fever sufferers.

Hay fever is an allergy to pollen or spores presenting as an allergic inflammatory response in all mucous membranes of the upper airway. The UK has one of the highest rates (it's estimated one in four of us have hay fever) and symptoms are often trivialised, even though the socio-economic and health costs are huge. If left treated, for example, a hay fever sufferer risks developing asthma. Also paediatric allergists now consider the combination of eczema and hay fever to be a significant marker, indicating an atopic child's propensity to develop more serious allergic disease. Unfortunately childhood hay fever is often poorly treated, but a combination of sensible allergen avoidance measures and appropriate medication or treatments is usually sufficient to control symptoms.

In vitro and in vivo Evaluation of the Efficacy and Safety of Powder Hydroxypropylmethylcellulose as Nasal Mucosal Barrier.

INTRODUCTION: Insufflation of powder hydroxypropylmethylcellulose (pHPMC) in the nose has been proven an effective barrier in subjects with rhinitis in many clinical studies. We conducted additionally in vitro and in vivo experiments to address outstanding efficacy and safety issues. METHODS: We used an experimental setup to demonstrate the inhibition of the diffusion of allergen extracts (house dust mite, Japanese cedar, Ragweed, Timothy grass) and pollutants (particulate matter 2.5 µm, PM2.5). Safety of pHPMC when insufflated in the airways of rats was assessed in 24 animals which were sacrificed; tissue sections from lungs, brain and liver were made 1, 24 and 48 hrs after pHPMC inhalation and compared to those of control animals. RESULTS: pHPMC acted as an effective barrier to diffusion of both the liquid allergen extracts and of PM2.5 into the agar covered slides: the quantities of the other tested allergens ranged between <0.5% and 14% of the quantities diffused in the void slides after 6 hrs. The quantity of PM2.5 penetrating the agar was reduced by 94%. Histological photomicrographs did not reveal any evidence of inflammation at 1, 24 and 48 hrs after pHPMC insufflation. CONCLUSION: Use of pHPMC should be viewed as a barrier enforcing measure against inhalatory ambient intruders.

PCR to predict risk of airborne disease.

Plant, animal and human diseases spread by microscopic airborne particles have had major economic and social impacts during history. Special air-sampling devices have been used to collect such particles since the 19th century but it has often been impossible to identify them accurately. Exciting new opportunities to combine air sampling with quantitative PCR to identify and count these particles are reviewed, using crop pathogen examples. These methods can be used to predict the risk of unexpected outbreaks of airborne diseases by identifying increases in pathogen inoculum or genetic changes in pathogen populations that render control ineffective. The predictions can provide guidance to policymakers, health professionals or the agricultural industry for the development of strategies to minimise the risk of severe pandemics.

Outdoor environments and human pathogens in air.

Are pathogens in outdoor air a health issue at present or will they become a problem in the future? A working group called AirPath - Outdoor Environments and Human Pathogens in Air was set up in 2007 at University College London, UK with the aim of opening new discussion and creating a research network to investigate the science and impacts of outdoor pathogens. Our objective in this paper is to review and discuss the following areas: What is the source of human pathogens in outdoor air? What current, developing and future techniques do we need? Can we identify at-risk groups in relation to their activities and environments? How do we prepare for the anticipated challenges of environmental change and new and emerging diseases? And how can we control for and prevent pathogens in outdoor environments? We think that this work can benefit the wider research community and policy makers by providing a concise overview of various research aspects and considerations which may be important to their work.

Regional importance of Alnus pollen as an aeroallergen: a comparative study of Alnus pollen counts from Worcester (UK) and Poznan (Poland).

Daily average Alnus pollen counts (1996-2005) from Worcester (UK) and Poznan (Poland) were examined with the aim of assessing the regional importance of Alnus pollen as an aeroallergen. The average number of Alnus pollen grains recorded annually at Poznan was more than 2.5 times that of Worcester. Furthermore, daily average Alnus pollen counts exceeded the thresholds of 100, 500 and 1,000 grains/m3 more times at Poznan than Worcester. Skin prick test results (1996-2005) and allergen-specific IgE (asIgE) measurements using the CAP (Pharmacia) system (2002-2005), were supplied by the Allergic Diseases Diagnostic Centre in Poznan. The annual number of positive skin prick tests to Alnus pollen allergens was significantly related (p<0.05) to seasonal variations in the magnitude of the Alnus pollen catch recorded at Poznan (r=0.70). The symptoms of patients with positive skin prick tests to Alnus pollen allergens were: 51% pollinosis, 43% atopic dermatitis, 4% asthma, 1% chronic urticaria and 1% eczema. On a scale of 0-6, 20.5% of patients examined for serum asIgE in relation to Alnus pollen allergens had asIgE measurements in classes 5 and 6. Alnus pollen is generally considered to be mildly allergenic. However, the amount of Alnus pollen released into the atmosphere in places such as Poznan may increase its impact on the population and make it one of the more important aeroallergens present.

Methyl-cellulose powder for prevention and management of nasal symptoms.

INTRODUCTION: HPMC-p, an inert micronized powder form of hydroxy-propyl-methyl-cellulose, when insufflated nasally, provides a natural barrier against pollen allergens and noxious agents. This overview assesses the efficacy and safety of this patented powder product and delivery system without an analogue among the cellulose derivatives. Areas covered: Twenty-six studies with HPMC-p were critically appraised to obtain an updated characteristic of the product. Most studies assessed the efficacy of HPMC-p as a nasal barrier enforcing measure: one experimental setup evaluated its ability to prevent or delay the diffusion of allergen through it, two clinical studies used allergen provocation tests, and the remaining relied on clinical criteria in open real world or placebo controlled designs. Two studies checked if HPMC-p could enhance the efficacy of drugs applied nasally to treat local symptoms. The studies, using either nasal allergen challenge or natural exposure of patients to environmental allergen, support the hypothesis that HPMC-p possesses barrier enforcing properties. Also, acute and clinical experiments indicated that intra-nasal application of HPMC-p following local relief medications enhances their ability to suppress symptoms and reduces their long-term use. Expert commentary: Nasal insufflation of HPMC-p provides a mucosal barrier, reducing the nasal symptoms and enhancing the effects of local relief medications.

Role of contact lenses in relieving ocular allergy.

PURPOSE: To examine the potential barrier and lubricating effects of modern daily disposable contact lenses (DD) against airborne antigens. METHODS: Ten patients with skin prick and ocular conjunctival provocation confirmed allergic sensitivity to grass pollen were recruited (average age 27.4 ± 7.7 years). Each had their ocular symptoms (on a 0 none to 5 extreme scale) and appearance of bulbar and limbal conjunctival redness, palpebral conjunctival redness and roughness, and corneal and conjunctival fluorescein staining (CCLRU scale) graded before and five minutes after exposure to 400 grains grass pollen/m(3) for 2 min in a purpose-designed exposure chamber to simulate the conditions of a 'very high' pollen-count day. This was repeated on three occasions separated by >72 h wearing etafilcon A (sDD), nelfilcon A with enhanced lubricating agents (ELDD) and no contact lenses in random order out of the pollen season. Each sign and symptom was compared to baseline for each condition. The duration of the symptoms was also recorded (http://www.clinicaltrials.govNCT01125540). RESULTS: Only symptoms of burning and stinging were significantly reduced in severity by ELDD (Chi-Sq = 7.6, p = 0.02), but overall symptoms were significantly reduced in duration (F = 3.60, p = 0.05). Bulbar hyperaemia, corneal and conjunctival staining, and palpebral conjunctival roughness were significantly reduced by DD wear (p < 0.01), with limbal and palpebral conjunctival redness further reduced in ELDD (p < 0.05). CONCLUSION: Daily disposable contact lenses offer a barrier to airborne antigen which is enhanced by modern lenses with enhanced lubricating agents.

Prevalence and impact of ocular allergy in the population attending UK optometric practice.

PURPOSE: To determine the prevalence of ocular allergy in patients attending optometric practices in the UK West Midlands and the impact this has on patients' daily lives. METHOD: Patients attending 9 optometric practices in the West Midlands, UK, were surveyed about the occurrence of ocular allergy, the severity of the symptoms and their treatment. Patients self-reporting ocular allergy were invited to complete a more detailed questionnaire. RESULTS: Of the 1904 consecutive patients assessed (mean age 47.7±23.2 years, 55% female), 13% reported an allergy, 8% an ocular allergy, rated as at least mild in 85% of cases. Medication was used by 77% of patients reporting ocular symptomology. Patients with ocular allergy (n=126) completed the detailed questionnaire. Seasonal symptoms occurred for 3.4±1.9 months of the year with a peak in June to July. The most common 'hayfever' type symptoms were itchy eyes and a runny nose, and ocular symptoms were itchiness and a desire to rub the eyes. Most had gained medication over the counter (73%) with advice from GPs (53%), pharmacists (41%) or a friend or relative (18%). Only 11% consulted an optometrist. Medication was mainly in the form of antihistamine tablets (71%), eye drops (40%) and nasal spray (40%). Those interested in a specialist ocular allergy service (83%) were willing to pay £15.50 on average. CONCLUSION: Ocular allergy is relatively common, but treatment is often self-managed, does not appear to totally overcome the discomfort and rarely involves a detailed eye examination.

Changes in the pollen seasons of the early flowering trees Alnus spp. and Corylus spp. in Worcester, United Kingdom, 1996-2005.

Previous work on Betula spp. (birch) in the UK and at five sites in Europe has shown that pollen seasons for this taxon have tended to become earlier by about 5-10 days per decade in most regions investigated over the last 30 years. This pattern has been linked to the trend to warmer winters and springs in recent years. However, little work has been done to investigate the changes in the pollen seasons for the early flowering trees. Several of these, such as Alnus spp. and Corylus spp., have allergens, which cross-react with those of Betula spp., and so have a priming effect on allergic people. This paper investigates pollen seasons for Alnus spp. and Corylus spp. for the years 1996-2005 at Worcester, in the West Midlands, United Kingdom. Pollen data for daily average counts were collected using a Burkard volumetric trap sited on the exposed roof of a three-story building. The climate is western maritime. Meteorological data for daily temperatures (maximum and minimum) and rainfall were obtained from the local monitoring sites. The local area up to approximately 10 km surrounding the site is mostly level terrain with some undulating hills and valleys. The local vegetation is mixed farmland and deciduous woodland. The pollen seasons for the two taxa investigated are typically late December or early January to late March. Various ways of defining the start and end of the pollen seasons were considered for these taxa, but the most useful was the 1% method whereby the season is deemed to have started when 1% of the total catch is achieved and to have ended when 99% is reached. The cumulative catches (in grains/m(3)) for Alnus spp. varied from 698 (2001) to 3,467 (2004). For Corylus spp., they varied from 65 (2001) to 4,933 (2004). The start dates for Alnus spp. showed 39 days difference in the 10 years (earliest 2000 day 21, latest 1996 day 60). The end dates differed by 26 days and the length of season differed by 15 days. The last 4 years in the set had notably higher cumulative counts than the first 2, but there was no trend towards earlier starts. For Corylus spp. start days also differed by 39 days (earliest 1999 day 5, latest 1996 day 44). The end date differed by 35 days and length of season by 26 days. Cumulative counts and lengths of season showed a distinct pattern of alternative high (long) and low (short) years. There is some evidence of a synchronous pattern for Alnus spp.. These patterns show some significant correlations with temperature and rainfall through the autumn, winter and early spring, and some relationships with growth degree 4s and chill units, but the series is too short to discern trends. The analysis has provided insight to the variation in the seasons for these early flowering trees and will form a basis for future work on building predictive models for these taxa.

A 30-day-ahead forecast model for grass pollen in north London, United Kingdom.

A 30-day-ahead forecast method has been developed for grass pollen in north London. The total period of the grass pollen season is covered by eight multiple regression models, each covering a 10-day period running consecutively from 21 May to 8 August. This means that three models were used for each 30-day forecast. The forecast models were produced using grass pollen and environmental data from 1961 to 1999 and tested on data from 2000 and 2002. Model accuracy was judged in two ways: the number of times the forecast model was able to successfully predict the severity (relative to the 1961-1999 dataset as a whole) of grass pollen counts in each of the eight forecast periods on a scale of 1 to 4; the number of times the forecast model was able to predict whether grass pollen counts were higher or lower than the mean. The models achieved 62.5% accuracy in both assessment years when predicting the relative severity of grass pollen counts on a scale of 1 to 4, which equates to six of the eight 10-day periods being forecast correctly. The models attained 87.5% and 100% accuracy in 2000 and 2002, respectively, when predicting whether grass pollen counts would be higher or lower than the mean. Attempting to predict pollen counts during distinct 10-day periods throughout the grass pollen season is a novel approach. The models also employed original methodology in the use of winter averages of the North Atlantic Oscillation to forecast 10-day means of allergenic pollen counts.