Airborne pollen concentrations and the incidence of allergic asthma and rhinoconjunctivitis in Lebanon

Abstract

Abstract Background Pollen monitoring is essential in the case of pollen-related allergic diseases. It may guide physicians and patients towards better prevention strategies, diagnosis, and treatment. Methods One hundred and twenty four patients suffering from rhinoconjunctivitis and/or asthma from different cities around the country, and consulting our allergy clinic between January 2008 and December 2008, were reviewed in a randomized, retrospective study. Skin prick-tests to a battery of perennial or seasonal allergens were performed to all patients during their visit. An airborne pollen investigation was performed in different cities around the country during this period. The Rhinoconjunctivitis Quality of Life (RQLQ) and the Asthma Quality of Life (AQLQ) questionnaires were used to assess the severity of symptoms. Results of the symptoms evaluation were then correlated to the peaks and total concentrations of airborne pollens. Results The airborne pollen sampling showed that Cupressaceae species were the dominant pollen persisting almost at all seasons. A tremendous surge in pollen count was noted in March at all stations with remarkably high level of pollen averaging about 400 pollen/m 3 /day in the one station. Pollens such as olive, and grass were noted as the spring developed. Urticaceae most likely of the Parietaria species, the pollen specific to the Mediterranean area was noted starting in the spring at all stations. The incidence of exacerbations of rhinoconjunctivitis or asthma was highest during the spring season with a frequency of 58.87%. There was another lower peak in the fall with a frequency of 23.3%. A total of 15.32% of patients were allergic to Cupressaceae; 73.68% of them experienced symptoms during spring and 52.63% during fall. A total of 17.75% were allergic to grass; 59.1% of these patients suffered of symptoms during spring and 36.36% during the fall. A total of 24.2% were allergic to Parietaria; 76.67% of these patients endured symptoms during spring and 43.3% during fall. A total of 16.2% were allergic to olive; 70% of these patients experienced symptoms during spring and 30% during fall. A total of 24.2% were allergic to mites; 36.67% of these patients experienced symptoms during spring and 30% during fall. Conclusion There was a good correlation between the peaks of the pollen count and the exacerbations of rhinoconjunctivitis and asthma symptoms. To our knowledge, this is the first study of clinical correlation with pollen count done in Lebanon. Continued monitoring and further studies will confirm our data, and support in better diagnosis and treatment of pollen-related allergic diseases.