الفهرس 
Pollen GrainsOnly 14 pages are availabe for public view
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Abstract
Allergens released from pollens are the triggers of seasonal rhinitis, conjunctivitis, and asthma, as well as an exacerbating factor of atopic dermatitis. This study aimed to determine the prevalence of allergy sensitization to the following pollen grains; short ragweed, rye grass, lamb’s quarters, English plantain, and wheat among children with allergic bronchial asthma and rhinoconjunctivitis, depict the peak pollination periods of these airborne pollen grains and their influence on the disease course (exacerbation and severity) and to elucidate the relationship between the atmospheric concentration of the studied pollen grains and the incidence of the allergic bronchial asthma and rhinoconjunctivitis during the period of the study.
We consecutively enrolled 200 patients with bronchial asthma, allergic rhinitis and allergic conjunctivitis. The patients were recruited from the Pediatric Pulmonology and Allergic Clinic, ENT and Ophthalmology Clinics, Children’s Hospital, Alexandria University. The study measurements were performed during the period from January 2011 to December 2011.
Clinical evaluation of the patients was done with special emphasis on the timing of exacerbations of symptoms and its severity. Skin prick testing (SPT) using commercial extracts of the five studied pollen grains was performed for each patient.
The present study showed that ryegrass pollen hypersensitivity in terms of positive SPT was the most frequent, being found in 14.9% (n=13) of asthmatic children and in 21.1% (n=12) of patients with allergic rhino-conjunctivitis. English plantain pollen hypersensitivity was the second common encountered in 8% (n=7) of asthmatic patients and in 10.7% (n=6) of patients with rhino-conjunctivitis. Wheat pollen hypersensitivity was the least frequent one, found in 4.6% (n=3) of allergic patients.
The type of the allergic disorder whether bronchial asthma, allergic rhinitis or allergic conjunctivitis did not have predilection for specific pollen allergy where the results of SPT to the studied pollen grains (short ragweed, rye grass, lamb’s quarters, English plantain and wheat) were comparable among the three groups. Six patients with different respiratory allergies found to have multiple pollen allergies with multiple positive SPT with specific predilection to lamb’s and rye grass pollen grains in three of them.
We found that the studied patients whether had bronchial asthma, allergic rhinitis or allergic conjunctivitis had comparable age. Also male to female distribution was comparable among the studied patients with different allergic disease. Else more, the frequency of positive family history of allergy was comparable among the studied patients whether they had bronchial asthma, allergic rhinitis or allergic conjunctivitis.
Additionally, in our study, the new cases of the studied allergic patients had comparable age to the old cases. Similar finding was observed as regard male to female proportion. Among the old cases, bronchial asthma was the predominant allergic disease being significantly more frequent when compared to the new cases. Allergic rhinitis and conjunctivitis were comparable among both groups.
Also the frequency of enrollment in different seasons was comparable among the old and new cases except for winter, which included significantly more frequent old than new cases. However, negative SPT to lamb’s quarters and English plantain pollen grains were found in all new cases. On the other hand, the frequency of positive SPT to short ragweed, rye grass and wheat pollen grains where comparable among the old and new cases of the studied sample.
Additionally, we found that the different seasons of exacerbation of symptoms among allergic patients did not have predilection for specific pollen allergy where the results of SPT to the studied pollen grains (short ragweed, rye grass, lamb’s quarters, English plantain and wheat) were comparable among the different seasons.
The frequency of positive SPT to English plantain and lamb’s quarters pollens was significantly higher among winter when compared with other seasons. On the other hand, the frequency of positive SPT to ragweed, rye and wheat pollen grains was comparable through different seasons of the year.
In our study, patients whether had bronchial asthma, allergic conjunctivitis or allergic rhinitis had comparable frequency of different seasonal exacerbation of the allergic diseases through different seasons of the year. However, patients with bronchial asthma had significantly more frequent visits during winter, while patients with allergic rhinoconjunctivitis were enrolled more frequently during autumn.
We found that pollen hypersensitivity in terms of positive SPT to the selected pollen grains (short ragweed, rye grass, lamb’s quarters, English plantain and wheat) did not affect the grade of asthma severity.
In conclusion, rye grass and English plantain were the most common pollen hypersensitivities among a group of children with respiratory allergies. No significant link was observed between any of the selected pollen grains hypersensitivity in terms of positive SPT and the different respiratory allergies studied namely the exacerbation or the severity of the disease. A national country based study of pollen hypersensitivities and quantification of atmospheric pollen load is needed to evaluate the impact on the prevalence and severity of allergic diseases.