Methods: we performed a prospective, clinical, observational research to determine the prevalence of sensitization to pollen produced by Casuarina equisetifolia and Pinus spp. Our ethical and investigation committee approved it. Every patient included in this research signed an informed consent before skin prick testing. We included patients with a clinical diagnosis of asthma, allergic conjunctivitis and allergic rhinitis. They all had a complete clinical evaluation and laboratory tests including complete blood count, nasal cytology, spirometry, serum total IgE and skin prick tests.
Results: We included 142 patients 3 to 50 years old who attended our clinic between may and june 2010. It included 44 children (36% females, 64% males) and 98 adults (73% females, 27% males). We found that 8 (18.18%) of the children and 35 (35.7%) of the adults had a positive skin prick test to Casuarina equisetifolia. None of the patients included in the study had a positive skin prick test to Pinus spp. We found a high prevalence of sensitization to Quercus and Alnus in those patients with a positive result to Casuarina equisetifolia.
Conclusions: : Casuarina species are found all around our city and can be a major source of pollen. In other countries, it has been demonstrated its importance as aeroallergens. We concluded it should be tested in our routine skin tests. More studies need to be done to determine the proteins involved in the cross reactivity to Quercus and Alnus. Pinus spp has traditionally been considered as non-allergic, despite some reports of their role as important aeroallergens in other countries. We couldn’t demonstrate its role as an important aeroallergen in our population.