Effect of tree and grass pollens and fungal spores on spring allergic rhinitis: a comparative study.

BACKGROUND: Current literature indicates tree pollen is less important than grass pollen as the cause of spring allergic rhinitis. The role of fungal spores is secondary and uncertain. OBJECTIVE: To assess the relative allergenicity of tree and grass pollen and fungal spores as the cause of spring allergic rhinitis in central Indiana. METHODS: (1) Chart review of 189 Indiana natives with seasonal allergic rhinitis to ascertain clinical sensitivity to tree or grass pollens. (2) A prospective study conducted in the spring of 1997 in 51 patients, correlating patients' symptom and medication scores with daily pollen and spore counts, obtained with a Burkard spore trap. RESULTS: One hundred thirty of 189 patients (69%) reported symptoms before May with positive prick test to at least one tree pollen. One hundred thirty-four patients (71%) had symptoms in May and June with positive test to grass pollen. The ratio between the two groups is 1:1, in contrast to a ratio of 1:4 derived from the literature. The prospective study revealed a symptom score increase parallel to the rise of tree pollen counts beginning in mid-March and reaching a plateau in early May prior to the onset of grass season. Medication use continued to increase and peaked at the height of grass pollination. Spore counts increased in late May and stayed at high levels throughout June, yet symptom and medication scores steadily declined following the peak of grass pollination in early June. CONCLUSIONS: This study suggests that in central Indiana, tree pollen is more important as the cause of spring allergic rhinitis than that suggested by the literature. This study confirmed previous observations that fungal spores are substantially less allergenic than pollens.     

High levels of Olea europaea pollen and relation with clinical findings.

BACKGROUND: Olea europaea pollen is an important cause of seasonal allergic rhinitis and bronchial asthma in southern Spain. For patients allergic to grass pol- len the critical concentration of airborn pollen is 50 grains/m3, but in the case of Olea pollinosis no data is available. METHODS: Fifty-six seasonal allergic rhinitis patients (29 in 1994 and 27 in 1995) were included in this study, all of whom lived in Jaen. Daily symptom card were filled in and pollen counts during May and June were performed in both years. A linear regression model was used for analysis of the airborne pollen concentration and the symptom score. RESULTS: Significant correlations among daily counts of Olea pollen and rhinitis symptoms were obtained. Most of our monosensitized patients needed a high Olea pollen concentration in the atmosphere (around 400 grains/m3) to suffer at least from mild allergic rhinitis symptoms. CONCLUSION: Local conditions with a wide area dedicated to olive tree cultivars result in a high concentration of this pollen in the atmosphere. Monosensitized Olea patients in our area seem to need exceptionally high levels to suffer from allergic symptoms.     

A relationship between birch pollen and meteorological factors during the past four years and pollen survey in Sapporo in 1997]

It is well known that grass pollinosis has been the most representative pollinosis in Hokkaido prefecture, Japan, However, it is also well known that birch (Japanese white birch, Betula platyphylla var. japonica) pollinosis is gradually increasing, which is marked especially in Sapporo and its neighborhood. We analyzed a relationship between the birch pollen count and meteorological factors statistically. Moreover, the principal airborne pollen counts in Sapporo in 1997 were assessed and compared with the previous pollen data. As a results of this study, it was showed a close relationship between the annual amounts of birch pollen and meterological factors of the year before, especially in May and June might be important. Moreover, there is a strong negative correlation between the birch pollen count and humidity, which seems to affect bringing up flower buds. As for the principal airborne pollen counts, some kinds of tree pollen, including birch pollen, were observed from the end of March, followed by grass (Gramineae) pollen in June and mugwort (Artemisia) pollen from the end of August, respectively. The annual amounts of grass pollen showed a decreasing trend.     

Clinical efficacy and safety of sublingual immunotherapy with tree pollen extract in children

BACKGROUND: Subcutaneous immunotherapy has been the principal approach of immunotherapy in the treatment of allergic diseases. Several clinical studies with birch, alder or hazel pollen extract conducted as subcutaneous immunotherapy have been published suggesting a well-tolerated and clinically effective treatment. Only a few clinical studies of sublingual immunotherapy (SLIT) with these allergens have been published. This study investigated the clinical efficacy, safety and dose-response relationship of SLIT in children suffering from rhinoconjunctivitis with/without asthma. METHODS: Eighty-eight children (5-15 years) with a history of tree pollen-induced allergic rhinoconjunctivitis with/without seasonal asthma for >or=2 years were included. Allergy to tree pollen was confirmed by positive skin-prick test, positive specific IgE and positive conjunctival provocation test. The extract used was a glycerinated mixture of Betula verrucosa, Corylus avellana and Alnus glutinosa 100,000 SQ-U/ml. Children were randomized into three groups receiving SLIT 5 days a week for up to 18 months; dose group 1: accumulated weekly dose of 24,000 SQ-U; dose group 2: accumulated weekly dose of 200,000 SQ-U; and placebo. RESULTS: In the birch pollen season, dose group 2 showed a significant reduction of symptom (P = 0.01) and medication scores (P = 0.04) compared with placebo. Dose group 1 showed a significant reduction of symptom scores (P = 0.03). There were no statistical differences between dose groups 1 and 2. All children tolerated the treatment well. CONCLUSION: SLIT with tree pollen extract provided dose-dependent benefits in tree pollen-allergic children in terms of significantly reduced symptoms and medication use. The treatment was well tolerated.     

Detection of Parietaria judaica airborne allergenic activity: comparison between immunochemical and morphological methods including clinical evaluation

Abstract. Airborne pollen grains und small plant particles of respirable size are the main causes of rhinitis and asthma in pollinosis patients. Consequently, it could be useful to quantify atmospheric variations in these biological aerosols and their allergenic activity as a basis for establishing correlations with the clinical symptoms in these allergic subjects. Our study was conducted in Naples from May to August 1992 and from May to August 1993 and concentrated on Perietaria judaica (Par j ) the most important hay fever-provoking plant in southern Italy. The aim of this study was lo evaluate the day-to-day variation in counts of Par j. pollen, the day-to-day variation in allergenic activity specific for this plant, and to relate these two variables to symptom scores in patients with respiratory allergy to Par j. The airborne pollen grains were collected by a Hirst-like volumetric trap and examined through an optical microscope, while the allergenic activity of particles trapped on glass fibre filters in a high volume air-sampler was determined by immunochemical assay. The two devices were placed on the flat roof of the "A. Cardarelli" Hospital. The results of this preliminary study suggest that both methods could have useful clinical relevance, since these two biological parameters were significantly correlated with the symptom scores of allergic patients. However, pollen count with morphological quantification of grains/m³ of air is a more simple technique.     

Pollen counts in relation to the prevalence of allergic rhinoconjunctivitis, asthma and atopic eczema in the International Study of Asthma and Allergies in Childhood (ISAAC)

BACKGROUND: Although pollens are major allergens associated with allergic rhinoconjunctivitis and asthma, there is little information about the relative prevalence of these conditions in populations with different pollen exposures. OBJECTIVE: The purpose of this study was to investigate the relationship between pollen exposure and allergic symptoms among children in different countries. METHODS: An ecological analysis was conducted to see whether pollen exposure (pollen counts, and duration and severity of pollen seasons) is associated with symptoms of allergic rhinoconjunctivitis, asthma and atopic eczema in 28 centres within 11 countries (nine being in Europe). Data on the prevalence of symptoms in 13-14-year olds were based on the responses to the written questionnaires from the International Study of Asthma and Allergies in Childhood (ISAAC). The analysis was adjusted for gross national product and mean annual relative humidity. RESULTS: There was little relationship between pollen exposure and symptom prevalence, except for a significant inverse association between grass pollen counts and lifetime prevalence of the symptoms of allergic rhinitis (P=0.03). Almost all the regression coefficients were negative. The associations were even weaker and all non-significant when the analyses were conducted within countries, using a random intercept fixed slope model, but there was still no evidence of a positive association between pollen exposure and symptoms. CONCLUSION: There is a weak but consistent tendency for the prevalence of allergic symptoms to be inversely associated with pollen exposure. This finding accords with evidence from several countries, suggesting that the prevalence of hayfever and asthma tends to be lower in rural than in urban areas, and lowest among people living on farms. Exposure to allergenic pollen in early life does not appear to increase the risk of acquiring symptoms of respiratory allergy, and may even give some protection against them.     

Correlation of environmental factors with asthma and rhinitis symptoms in Tulsa, OK.

BACKGROUND: Airborne allergens, pollutants, and climatic changes are known to influence the symptoms of asthma patients. OBJECTIVE: To correlate airborne fungal spore and pollen concentrations, meteorological data, and airborne pollutants with asthma and rhinitis symptoms to develop predictive models for asthma severity. METHODS: Patients from the Tulsa community participated in this study from September 1 to October 31, 2000, by filling out daily symptom diaries and measuring morning and evening peak expiratory flow rates. Air samples were collected using a volumetric spore trap. Meteorological variables and maximum and average pollutants were also included in the analysis. Linear regression analyses were performed for all environmental variables and symptom scores. Forward stepwise multiple regression analyses were performed to determine sets of variables that could be used to predict the conditions of increased symptom severity. RESULTS: Twenty-four patients participated in this study. The predominant spore types included Cladosporium, ascospores, and basidiospores. The predominant pollen type was Ambrosia. September was unusually hot and dry in Tulsa, but 161 mm of precipitation fell in October, primarily during the last 11 days. Two periods of peak symptoms occurred during the study, the first during the peak week of Ambrosia and the second after a 22 degrees C drop in temperature over 6 days. Numerous environmental variables showed significant correlations with symptom scores; however, there was no single predictive model for all symptoms. CONCLUSIONS: Ambrosia pollen and other environmental variables, including ozone levels, were significantly correlated with asthma and rhinitis symptoms.     

Lack of correlation between regional pollen counts and percutaneous reactivity to tree pollen extracts in patients with seasonal allergic rhinitis.

BACKGROUND: Although seasonal patterns of tree pollination have been reported, it is unknown if aerobiologic data correlate with patterns of in vivo sensitization. OBJECTIVE: To evaluate the relationship between regional tree pollen exposure and patterns of in vivo percutaneous reactivity to specific tree pollen extracts in a local patient population with seasonal allergic rhinitis. METHODS: Patients with spring seasonal allergic rhinitis and percutaneous sensitivity to 1 or more regional tree pollens were studied. Tree pollen counts were collected at the same urban site from 1997 to 2002 and at a suburban site in 2002. Patients underwent skin prick testing with commercial extracts of 15 indigenous tree species. Serum specific IgE measurements were assayed in a subset of sensitized patients. RESULTS: Of 127 patients who reported symptoms consistent with seasonal allergic rhinitis during the spring pollen season, 93 qualified based on demonstration of at least 1 positive skin prick test result. Mean 5-year pollen counts (1997-2001) and 2002 urban counts were highly correlated (Spearman r = 0.95, P < .001), indicating that year-to-year pollen counts were consistent. No significant correlation was found between mean seasonal pollen counts (urban site, 1997-2001) and frequencies of skin prick test reactivity to specific tree pollen allergens (Spearman r = -0.03, P = .93). No significant relationship was found between 5-year mean tree pollen counts and positive serum specific IgE tests for specific tree pollens (Spearman r = -0.42, P = .30). Eight of 15 species elicited percutaneous reactions in more than 50% of patients (ie, satisfying definition of a major in vivo allergen). However, 6 of the 8 major tree allergens each represented 5% or less of 5-year mean total tree pollen counts. CONCLUSION: No correlation was found between overall frequencies of in vivo sensitization to tree pollen allergens in a local population and regional pollen exposure data.     

Effect of montelukast on symptoms and exhaled nitric oxide levels in 7- to 14-year-old children with seasonal allergic rhinitis.

BACKGROUND: Cysteinyl leukotrienes have been found to exert potent inflammatory effects in the upper airways and play a fundamental role in the pathogenesis of allergic rhinitis. Previous studies have reported increased levels of exhaled nitric oxide (eNO) in patients with allergic rhinitis without asthma symptoms. OBJECTIVE: To investigate the role of treatment with montelukast on symptoms, eNO levels, and peripheral eosinophil counts of children with seasonal allergic rhinitis during pollen season. METHODS: A randomized, double-blind, parallel-group study performed between April and June 2005 in 57 children aged 7 to 14 years with seasonal allergic rhinitis was performed. The study comprised a 1-week screening period, a 1-week run-in period, and a 2-week treatment period with once daily montelukast, 5 mg, or matching placebo. RESULTS: No significant difference at baseline was found in symptom scores, eNO levels, and blood eosinophil counts between the treatment and placebo groups. After 2 weeks of montelukast treatment, improvements from the baseline in the daytime nasal, composite, and daytime eye symptoms scores were significantly greater in the montelukast group compared with the placebo group (P < .001, P < .001, and P < .01, respectively). A significant decrease was also found in eosinophil counts (P < .001) in the montelukast group compared with the placebo group after treatment. Montelukast treatment did not produce a significant effect on eNO levels compared with placebo (P = .96). CONCLUSION: Montelukast treatment provided significant improvement in symptoms and peripheral eosinophil counts of school-age children with seasonal allergic rhinitis; however, it did not show a significant effect on eNO levels.     

Serum eosinophil cationic protein level and disease activity in childhood rhinitis

In order to investigate clinical markers of disease activity in childhood rhinitis, we compared various laboratory parameters to symptom scores of children with allergic rhinitis and non-allergic rhinitis. We measured the levels of serum total IgE, aeroallergen specific IgE, serum eosinophil cationic protein (ECP), and blood eosinophil counts in 71 children with allergic rhinitis and in 62 children with non-allergic rhinitis. We found a statistically significant difference in peripheral blood eosinophil counts between the allergic rhinitis and non-allergic rhinitis groups. Serum ECP levels were positively related to symptom scores in both groups. Peripheral blood eosinophil counts correlated with symptom scores only in the group with non-allergic rhinitis. The results demonstrated that serum ECP levels are of value in assessing disease activity in both allergic and non-allergic rhinitis, and peripheral blood eosinophil counts may play a role in the evaluation of symptom severity in non-allergic rhinitis.     

深圳市春季气传致敏花粉的调查

目的探讨深圳市气传花粉的种类、数量及季节消长规律,为本地区防治花粉症防治提供有效资料。方法应用Burkard采样器于2007年2月1日至2007年4月30日对深圳市气传花粉浓度进行监测,并对花粉浓度进行统计学分析。结果本次调查共曝片178张,1.5 m和30 m两个高度采集点各89张。曝片共识别花粉43种,23 810粒,其中1.5米高度较多,14 796粒,占总数62.1%;30米高度较少,9 014粒,占总数37.9%。曝片所见以木本花粉为主,松科花粉最多,其他依次为:木麻黄科、杉科、禾本科、大戟科、桃金娘科、无患子科、杨柳科等。结论深圳市空气中气传花粉飘散种类、数量及季节分布规律的调查结果,可以为本地区花粉症防治及绿化品种的选择提供可靠依据。     

A comparative, volumetric survey of airborne pollen in Philadelphia, Pennsylvania (1991-1997) and Cherry Hill, New Jersey (1995-1997).

BACKGROUND: Aeroallergen sampling provides information regarding the onset, duration, and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. OBJECTIVE: This atmospheric survey reports: 1) airborne pollen contributors in Philadelphia, Pennsylvania (1991 to 1997) and suburban Cherry Hill, New Jersey (1995 to 1997); 2) pollen onset, duration, and peak level; and 3) the relationship between airborne pollen and selected meteorologic variables. METHODS: At both locations, separated by 11 km. sampling was performed with a volumetric Rotorod Sampler (Sampling Technologies, Minnetonka, MN). RESULTS: In Philadelphia and Cherry Hill, respectively, 3-year average measurements included 75.0 and 74.2% tree pollen, 10.2 and 8.3% grass pollen, and 14.8 and 17.5% weed pollen. Prominent airborne pollen taxa were Acer, Quercus, Betula, Pinus, Cupressaceae, Poaceae, Ambrosia, and Rumex. The tree, grass, and weed pollen seasons extended from mid-March to mid-June, late April to mid-June, and mid-August to late September, respectively. A secondary Poaceae pollen peak occurred in September. There was a statistically significant correlation between simultaneous weekly average pollen levels in Philadelphia and in Cherry Hill (Acer, r(p) = 0.987, Quercus, r(p) = 0.645, Betula, r(p) = 0.896, Pinus, r(p) = 0.732, Cupressaceae, r(p) = 0.695, Poaceae, r(p) = 0.950, Ambrosia, r(p) = 0.903, and Rumex, r(p) = 0.572, P <0.001). Daily Poaceae pollen levels were positively influenced by same-day high temperature (r(s) = 0.333 in Philadelphia and r(s) = 0.426 in Cherry Hill, P < 0.05). Daily Ambrosia pollen levels were inversely influenced by same-day total precipitation (r(s) = -0.174 in Philadelphia and r(s) = -0.257 in Cherry Hill, P < 0.05). CONCLUSIONS: This is the first volumetric survey performed in either Philadelphia or Cherry Hill. Copious amounts of airborne pollen were seen from late April to early May and in early September. Pollen onset, duration, and year-to-year variability were similar at both sites. An awareness of local aeroallergen patterns is critical in the effective testing and treatment of atopic individuals.     

Studies on Pollen Allergy in Delhi

The volumetric sampling of the air has been earned out with the Suction Impaction Sampler devised by Tilak & Kulkarni (1970). The pollen counts have been expressed as number per cubic metre volume of the air. Based on the percentage of pollen peaks, diurnal patterns of the total count of all the types, and six dominant allergens have been determined. For these allergens, daily fluctuations have also been recorded. The influence of meteorological factors such as temperature, wind, rainfall, relative humidity and sunshine hours/day on the variation patterns in the concentration of atmospheric pollen has been discussed. It has been shown that 25–30°C temperature, 5–15km/h wind speed, 60–70°, RH, bright, sunny and rain-free days are favourable for high pollen catch. These weather conditions might be conducive for the high discharge, dispersal, and deposition of air-borne pollen. Too low or too high temperature, very high wind speed, high humidity, and cloudy and rainy days hinder high pollen catch.     

Hourly variation of airborne ragweed pollen in Kansas City.

INTRODUCTION: Ragweed pollen is one of the major causes of allergic rhinitis in the midwest United States. Previous studies have demonstrated that ragweed pollen production begins after sunrise and airborne pollen levels peak several hours later. Variations in this pattern that may be of clinical importance within a small region and the effect of weather on these variations have not been investigated. METHODS: Volumetric pollen collectors were stationed at four sites around the metropolitan area. Ten-minute grab samples were taken at each location every 2 hours for continuous 24-hour periods during the 1997 ragweed season. The downtown location had a weather station that logged meteorological conditions at hourly intervals during this time. Ragweed pollen grains were counted microscopically at 400 x. Uninterrupted data covering at least 20 days during the season were evaluated for each collection site. RESULTS: The lowest ragweed pollen counts occur at 6:00 AM and the highest occur at noon for both suburban and urban sites. Rainfall was seen to be the most influential weather-related factor. Significant rainfall events effectively removed pollen grains from the air. CONCLUSIONS: Though ragweed pollen emission begins at 6:00 AM, peak pollen exposure occurs at midday. This observation is in agreement with many other studies. The myth that highest ragweed exposure occurs in the early morning hours is not supported by this or previous studies.     

Prediction of annual variations in atmospheric concentrations of grass pollen. A method based on meteorological factors and grain crop estimates

We performed an aerobiologic observation of the grasses present in Madrid for 14 years (1978-1991), using volumetric air samplers. The counts obtained show that the major grass pollen release period (average daily grass pollen counts greater than 50 grains/m3 of air) occurs in the months of May and June, although lower counts can occur some days from the end of January onward. There are wide year-to-year variations in total atmospheric grass pollen counts, expressed as the total sum of the mean daily concentrations from April 1st to July 30th (ranging from 2568 to 6624). A strong, statistically significant correlation, based on Spearman's rank test and/or simple and multiple linear regressions, was found between the total grass seasonal count and preseasonal rainfall from October to March (R2 = 0.64; P = 0.0429). The meteorological variable which gave the correlation with greatest statistical significance (R2 = 0.97; P = 0.0016) was the average monthly preseasonal humidity from October to March. A good correlation was also found between March estimates of wheat, rye and barley crops and the total grass count (R2 = 0.73; P = 0.006). A model was designed from the above mentioned humidity variable through a multilinear regression analysis, and it was possible to predict, at the beginning of April, total seasonal counts for 1989 (predicted = 5468; actual = 4410; average error = 24%), 1990 (5033; 6090; -17%) and 1991 (3930; 2568; 53%). These data may help clinicians to predict and prepare themselves for the intensity of the grass pollen season and to explain yearly variations in the severity of symptoms.     

Air pollutants enhance rhinoconjunctivitis symptoms in pollen-allergic individuals.

BACKGROUND: Little is know about the relation of airborne pollen allergens to nasal and ocular symptoms in combination with air pollutants. OBJECTIVE: The hypothesis was that air pollutants exacerbate allergic symptoms of the nose and eyes during the pollen season. In addition, the use of allergen measurements instead of pollen counts should be tested. METHODS: Fifteen pollen-allergic, nonsmoking subjects with weak reactivity of the airways recorded rhinoconjunctival symptoms and medication every morning and evening throughout the pollen season. Symptoms were compared with air pollutants (nitrogen oxide [NOx], particulate matter smaller than 10 microm, and ozone) and birch and grass pollen counts or, alternatively, to airborne birch and grass allergens determined using ELISA-techniques. A multiple linear regression model was used which controlled for autocorrelation of the residuals of the time series (Cochrane-Orcutt approach). This model was applied to each subject individually, followed by calculations of summary scores for the group. RESULTS: Air pollution levels were moderate, often meeting air quality standards. Effect estimates (increase of score with 10-fold increase of concentration) were NOx = 1.06, P < 0.01; ozone = 1.59, P < 0.01; and pollen = 0.48, P < 0.001. Using allergen concentrations instead of pollen counts resulted in similar effect estimates. Using particulate matter smaller than 10 microm instead of NOx gave comparable but less consistent results. CONCLUSIONS: Symptoms were related to moderate levels of pollutants, suggesting that rhinoconjunctival tissue is very sensitive to irritant stimuli during an ongoing allergic inflammation, and that susceptibility toward allergens might be increased in areas with increased levels of air pollutants. Allergen measurements seem equally usable as pollen counts to investigate rhinoconjunctivitis.     

Forecasting pollen pollution: correlation with floral development

Variations in the time course of flowering and in its intensity were recorded for regions in Israel along with variable climatic conditions. Such variations had an effect on pollen release into the air and on pollen counts. Two approaches for forecasting allergenic pollen dispersion were compared: (1) a survey of floral development and flowering intensity and (2) a survey of airborne pollen. There was a positive correlation between the survey of flowering and airborne pollen counts, although pollen was occasionally found after the flowering season. Further, it predicted fairly accurately the beginning of the flowering time of each species in each regio, the expected flowering duration, and intensity. Conducting a survey of flowering is a simple, easy and inexpensive operation. It is highly recommended for regions with variable climates.     

Interpreting atmospheric pollen counts for use in clinical allergy: allergic symptomology.

BACKGROUND: Allergists generally consider atmospheric pollen counts to be an estimate of the antigenic challenge confronting allergic individuals. The nature of this challenge depends on the particular pollen types found in the atmosphere and also the airborne concentration of these pollen types. Both clinical experience and clinical investigations support these assumptions; however, a coherent system for relating pollen counts and allergic symptomology does not exist. OBJECTIVE: This review article will systematically review the medical and technical literature concerning the clinical significance of atmospheric pollen counts. Data sources: This review article will consider three independent bodies of literature: 1) data contrasting human exposure patterns with rooftop pollen counts; 2) data concerning dose-response relationships between atmospheric pollen counts and allergic symptomology; and 3) data concerning methods for indexing atmospheric pollen counts based on a pollen type's in vivo allergenicity and terminal velocity. RESULTS: Three principal results emerged. First, rooftop pollen counts imperfectly approximate human exposure to atmospheric pollen. Differences in both the concentration and type of pollen encountered by humans can be expected to differ from samples obtained on rooftops. Second, allergic symptomology is positively correlated with atmospheric pollen counts. Investigations involving Betula (birch) pollen offer quantitative dose-response models. Complex, nonlinear relationships that seem to reflect both the priming effect and late-phase reactions exist. Last, atmospheric pollen counts can be indexed based on a contemporary application of Thommen's postulates. This system provides allergists with a means to estimate the clinical significance of various pollen types by combining data concerning in vivo allergenicity and terminal velocity. CONCLUSIONS: These conclusions should allow allergists to judge the clinical significance of atmospheric pollen counts with greater sophistication than was previously possible.     

Airborne pollen concentrations and the incidence of allergic asthma and rhinoconjunctivitis in northern Italy from 1992 to 2003

BACKGROUND: Aeroallergens and the environment play an important role in the pathogenesis of respiratory allergies. In a 12-year study carried out in Northern Italy (geographic area of Parma), the effects of airborne pollen and meteorological conditions on the incidence of allergic asthma and rhinoconjunctivitis were evaluated. PATIENTS AND METHODS: Among 9,060 subjects examined for respiratory pathologies at our Allergy Unit, Parma Hospital, Italy, from 1992 to 2003, only 1,054 positive to only one type of inhalant allergen in the skin prick test were studied, to avoid bias of cross-reactivity. Allergy and clinical aspects were compared with the duration of the pollination period, and peaks and total concentrations of airborne pollen. RESULTS: Our data showed a significantly growing trend of allergy to mites, pets and birch pollen and a significant increase in asthma, and a significantly decreasing trend of positive reactions to grasses and a decrease in rhinoconjunctivitis. At the same time, there was a significant decrease in total pollen counts, concentration peaks and pollination period of grasses. A significant increase was only observed in ragweed and ash-olive total and peak pollen concentrations. CONCLUSIONS: Significant correlations between the increasing incidence in asthma and allergy to mites, pets and birch pollen are shown. The decrease in the total pollen count and concentration peaks of grass pollen was correlated to the decreasing trend of rhinoconjunctivitis. The trend of increasing concentrations of ash-olive and ragweed pollen was not accompanied by an increase in the related allergy.     

Oxatomide in the management of hay fever–a placebo-controlled double-blind study in general practice

Sixty-three patients completed a double-blind placebo-controlled study of oral oxatomide (30 mg t.d.s.) in the management of seasonal allergic rhinitis and/or conjunctivitis. Hay fever symptom scores were significantly lower for oxatomide-treated patients than for the placebo group on the majority of days during periods of high pollen counts. Moreover, on days when pollen counts were 10/m³ or more, a statistically significant positive correlation between symptom score and pollen count was demonstrated for the placebo group but not for the oxatomide group. Oxatomide also appeared to be superior to placebo in terms of patients' requirements for supplementary mepyramine (Anthisan) tablets, and the doctor's global assessment. Side-effects were reported by four patients in the oxatomide group and by three receiving placebo.