Pollen sensitization among Egyptian patients with respiratory allergic diseases

Pollen is responsible for seasonal allergies, such as allergic rhino-conjunctivitis (AR), and has become a growing public health concern. Climate change affects the range of allergenic species as well as the timing and length of the pollen season. In Egypt, data on pollinosis are scarce. This study aimed to identify the most prevalent pollen causing allergies among Egyptian patients with respiratory allergies. A total of 200 patients with respiratory allergic diseases, allergic rhinitis and/or bronchial asthma (BA), were included. Medical history taking and physical examinations were conducted on each patient. Complete blood count (CBC), total immunoglobulin E (IgE) determination, spirometry, specific IgE, and skin prick tests (SPTs) for common aeroallergens and food were performed. Of the 200 patients, 106 (53%) were females. The age of study subjects ranged 16-66 years (mean ± SD, 34.42 ± 13.0), and 65% were living in urban areas. Grass pollen, mainly from Timothy grass and maize, were the most prevalent allergens (28.5%). Timothy grass was the most common type of pollen in patients with AR (28.3 %). Elder pollen was more prevalent among asthmatic patients (P = 0.004). Bermuda grass was statistically more prevalent in rural than in urban areas (P = 0.008). Maize was linked to uncontrolled BA, whereas Timothy grass was the most prevalent among patients with moderate/severe AR. Forty-three patients had oral allergy syndrome; oranges and tomatoes were the most cross-reactive food allergies (12% and 11.5%, respectively). Exacerbation of allergic symptoms was noted during January, December, March, and June. In conclusion, pollen plays a substantial role in affecting patients with respiratory allergies in Egypt. Grass pollen is the most prevalent type of pollen, especially in urban areas.