Abstract
Purpose
The aim of the study was to determine the epidemiologic profile of Alternaria alternata (AA)–sensitized patients with allergic rhinitis including coexistence of other atopic diseases, seasonal distribution of AA aeroallergens, age of onset of AA sensitization, and prevalence of sensitization to other allergens.
Materials and methods
History, clinical examination, and skin prick tests were performed in 623 patients with allergic rhinitis from central Greece. Patients’ age, cosensitization, place of living, seasonal distribution, and concomitant symptoms were the variables used to discriminate between AA-sensitized and non–AA–sensitized patients. Significant predictor variables for AA sensitization were determined.
Results
A alternata sensitization was associated with male sex, age younger than 18 years, living in new-built apartments in urban and semiurban areas by the sea, perennial distribution, and nonsmoking. A alternata –sensitized patients were affected more frequently by asthma than non–AA-sensitized patients. No significant differences were found in frequency of bronchitis, cough, conjunctivitis, urticaria, or eczema between patients sensitized or not to AA. Most (66.7%) of AA-sensitized patients were oligosensitized, 18.5% of patients were polysensitized, and 14.8% were monosensitized. Patients’ age, cosensitization, place of living, and seasonal distribution were the significant predictor variables discriminating AA-sensitized from non–AA-sensitized patients. These variables correctly classified 79.7% of the patients. A alternata –sensitized patients were more frequently sensitized to grasses, cat epithelia, and flours-rye and less frequently sensitized to artemisia, Dermatophagoides pteronyssinus , D farinae , and chenopodium.
Conclusions
Patients meeting the aforementioned epidemiologic criteria should be preferentially offered skin prick tests for AA sensitization.
1
Introduction
Allergic rhinitis (AR) affects 25% of the European population . Atopic sensitization to the mould Alternaria alternata (AA) has been associated with rhinitis and asthma . Treating rhinitis might prevent asthma development . However, AA sensitization still remains underdiagnosed in many countries . It is therefore crucial to identify early individuals at risk, especially children, for AA sensitivity .
Little is known about the significance of AA as a risk factor for asthma because established factors for AA sensitivity have changed, including air pollution, lifestyle, food habits, air-conditioning and air heating, construction of new buildings with new materials, and ventilation systems. In addition, there is variability in epidemiologic data regarding geographical, climatic, and seasonal changes even within the same broader region . The actual prevalence of sensitization to AA mold is difficult to determine because of differences in diagnostic criteria in study design and unreliability of diagnostic extracts. In addition, to our knowledge, there is a lack of such epidemiological data in the Greek population.
The aims of our study were (1) to determine the prevalence of AA sensitization in respiratory allergic patients, (2) to explore the association of AA sensitization to other atopic diseases, (3) to examine the seasonal distribution of AA aeroallergens, (4) to estimate the age of onset of AA sensitization, and (5) to determine the prevalence of mono-, oligo- and multiple sensitization to other allergens in patients with AA sensitization.
2
Materials and methods
In this prospective study, 623 patients from central Greece (Thessaly) were included . Patients from all 4 distinct prefectures of Thessaly (Larissa, Magnisia, Karditsa, and Trikala) were examined. Thessaly was chosen because there were no studies on the allergic profile of the respective population, and its climate conditions and geography are representative for the Mediterranean area. On the humid coastal strip of Magnisia, mean temperatures range from 3°C to 12°C in the winter to 20°C to 32°C in summer. The drier inner provinces of Trikala and Karditsa exhibit larger temperature variation between seasons, whereas Larissa is notorious for wet climate and high annual temperatures. The land is 45% mountainous or semimountanous and 55% lowland.
Patients complaining for rhinitis symptoms were recruited by general practitioners, otorhinolaryngologists, pediatricians, and pneumonologists from all 4 prefectures. A detailed history, clinical examination, and skin prick tests (SPTs) were performed. The study protocol was approved by the local institutional review board. All subjects were volunteers, and they have been informed about the study’s aim, design, and clinical implications. The investigations were performed in accordance with the Declaration of Helsinki/Hong Kong.
Patients with AA sensitivity were 48 men (59.3%) and 33 women (40.7%) with a mean age of 15.94 ± 8.79 years (range, 7-67 years). Patient demographics are presented on Table 1 .
| AA | Other aeroallergens | P | |||
|---|---|---|---|---|---|
| No. of patients | (%) | No. of patients | (%) | ||
| Sex | .050 | ||||
| Female | 33 | 40.7 | 284 | 52.4 | |
| Male | 48 | 59.3 | 258 | 47.6 | |
| Age, y | <.001 | ||||
| ≤18 | 57 | 70.4 | 133 | 70.4 | |
| >18 | 24 | 29.6 | 409 | 29.6 | |
| Mean age ± SD | 15.94 ± 8.79 | 31.72 ± 15.83 | |||
| Median (IQR) | 13 (10–20.5) | 30 (19–43) | |||
| Contact to animals | .822 | ||||
| No | 48 | 59.3 | 314 | 57.9 | |
| Yes | 33 | 40.7 | 228 | 42.1 | |
| Residence | .008 | ||||
| Urban areas | 58 | 71.6 | 316 | 58.3 | |
| Semiurban areas | 16 | 19.8 | 130 | 24.0 | |
| Agricultural areas | 7 | 8.6 | 130 | 17.7 | |
| Geographic area | .021 | ||||
| Mainland | 77 | 95.1 | 487 | 89.9 | |
| Coastal | 4 | 4.9 | 14 | 2.6 | |
| Mountainous | – | – | 41 | 7.6 | |
| Type of house | .125 | ||||
| Flat | 38 | 46.9 | 192 | 35.4 | |
| Detached house | 37 | 45.7 | 292 | 53.9 | |
| Farm | 6 | 7.4 | 58 | 10.7 | |
| Age of house | .011 | ||||
| Old | 24 | 29.6 | 242 | 44.6 | |
| New | 57 | 70.4 | 300 | 55.4 | |
| Smoking | .005 | ||||
| No | 71 | 87.7 | 397 | 73.2 | |
| Yes | 10 | 12.3 | 145 | 26.8 | |
| Concomitant symptoms | |||||
| Asthma | 47 | 58.0 | 233 | 43.0 | .011 |
| Bronchitis | 42 | 51.9 | 231 | 42.6 | .118 |
| Conjuctivitis | 28 | 34.6 | 183 | 33.8 | .887 |
| Urticaria | 15 | 18.5 | 86 | 15.9 | .546 |
| Eczema | 10 | 12.3 | 62 | 11.4 | .812 |
| Cough | 26 | 32.1 | 133 | 24.5 | .145 |
| Seasonal distribution | <.001 | ||||
| Persistent | 66 | 81.5 | 323 | 59.6 | |
| Intermittent | 15 | 18.5 | 219 | 40.4 | |
| No. of allergens | <.001 | ||||
| Monosensitivity | 12 | 14.8 | 226 | 41.7 | |
| Oligosensitivity | 54 | 66.7 | 275 | 50.7 | |
| Polysensitivity | 15 | 18.5 | 41 | 7.6 | |
All patients underwent SPTs with a panel of 20 commercial allergenic extracts (Allergopharma, Reinbeck, Germany) selected upon known local presence ( Table 2 ). There was no current use of any antihistamine drugs within the preceding 30 days or systemic corticosteroids, leukotriene inhibitors, and immunotherapy within the last 28 days. All allergens were standardized, and most were single extracts; only 2 solutions were mixes: “grasses’ mix” and “feathers’ mix.” More than twice the recommended number of tested allergens were included to achieve a more thorough investigation. Histamine dihydrochloride (10 mg/mL) was the positive control, and the extracts’ solvent (glycerin) was the negative control.
| AA-sensitive patients | Patients sensitive to other aeroallergens | P | |||
|---|---|---|---|---|---|
| n | (%) | n | (%) | ||
| Type of aeroallergen | |||||
| Grasses mix | 47 | 58.0 | 295 | 54.4 | .544 |
| Feathers—duck, goose, hen | 0 | 0.0 | 3 | 0.6 | .502 |
| Artemisia vulgaris | 1 | 1.2 | 43 | 7.9 | .028 |
| Plantain | 3 | 3.7 | 32 | 5.9 | .422 |
| Epithelia of animals, dog | 3 | 3.7 | 24 | 4.4 | .765 |
| Epithelia of animals, cat | 22 | 27.2 | 82 | 15.1 | .007 |
| Epithelia of animals, goat | 1 | 1.2 | 4 | 0.7 | .640 |
| Cladosporium | 9 | 11.1 | 15 | 2.8 | <.001 |
| Aspergillus | 6 | 7.4 | 13 | 2.4 | .014 |
| D pteronyssinus | 16 | 19.8 | 222 | 41.0 | <.001 |
| D farinae | 22 | 27.2 | 232 | 42.8 | .008 |
| Flours, wheat | 1 | 1.2 | 4 | 0.7 | .640 |
| Flours-rye | 2 | 2.5 | 3 | 0.6 | .072 |
| Olive | 25 | 30.9 | 157 | 29.0 | .726 |
| Parietaria | 6 | 7.4 | 58 | 10.7 | .362 |
| Chenopodium | 2 | 2.5 | 44 | 8.1 | .070 |
| Hornbeam, Caprinus detulus | 1 | 1.2 | 15 | 2.8 | .416 |
| Cypress | 10 | 12.3 | 65 | 12.0 | .927 |
| Bermuda grass | 35 | 43.2 | 225 | 41.5 | .773 |
Wheal and flare sizes were measured in millimeters in 2 perpendicular directions at 20 minutes after the initial skin prick and considered positive only when wheals of at least 3 mm and flares of at least 10 mm in diameter larger than the negative control were found. Subjects with negative responses to all 20 aeroallergens were considered nonallergic. Subjects sensitized to only 1 allergen were referred as “monosensitized,” to 2 or 3 allergens as “oligosensitized,” and to 4 or more allergens as “polysensitized.”
Statistical analysis was performed using the Statistical Package for the Social Sciences, version 14.0 (SPSS Inc, Chicago, IL). Age was expressed as the mean ± SD. All other variables were categorical; they were expressed as frequencies and percentages (%) and analyzed using the χ 2 test. Odds ratios (ORs) and their 95% confidence intervals (95% CIs) were calculated using simple logistic regression analysis as the measure of association between AA sensitization and (1) patients’ demographic characteristics, (2) concomitant symptoms/conditions, and (3) sensitization to other aeroallergens. Discriminant forward stepwise analysis was used to determine the significant predictor variables that provide the best discrimination between sensitization or not to AA. All tests were 2 tailed, and statistical significance was considered for P < .05.
2
Materials and methods
In this prospective study, 623 patients from central Greece (Thessaly) were included . Patients from all 4 distinct prefectures of Thessaly (Larissa, Magnisia, Karditsa, and Trikala) were examined. Thessaly was chosen because there were no studies on the allergic profile of the respective population, and its climate conditions and geography are representative for the Mediterranean area. On the humid coastal strip of Magnisia, mean temperatures range from 3°C to 12°C in the winter to 20°C to 32°C in summer. The drier inner provinces of Trikala and Karditsa exhibit larger temperature variation between seasons, whereas Larissa is notorious for wet climate and high annual temperatures. The land is 45% mountainous or semimountanous and 55% lowland.
Patients complaining for rhinitis symptoms were recruited by general practitioners, otorhinolaryngologists, pediatricians, and pneumonologists from all 4 prefectures. A detailed history, clinical examination, and skin prick tests (SPTs) were performed. The study protocol was approved by the local institutional review board. All subjects were volunteers, and they have been informed about the study’s aim, design, and clinical implications. The investigations were performed in accordance with the Declaration of Helsinki/Hong Kong.
Patients with AA sensitivity were 48 men (59.3%) and 33 women (40.7%) with a mean age of 15.94 ± 8.79 years (range, 7-67 years). Patient demographics are presented on Table 1 .
