Dust mites but not grass pollen are important sensitizers in asthmatic children in the Ecuadorian Andes

Grass pollen is an important cause of asthma and rhinoconjunctivitis in Eur ope and the United States. In the high Andes however, the role this pollen plays in respiratory allergies is unknown. In this study we tested the prev alence of grass pollen sensitization in comparison to other aeroallergens o n 433 asthmatic children living in Quite, Ecuador (the Andes mountain range , 2,800 m above sea level). The skin prick test technique was used. We foun d that the least sensitizing allergens of all were grass pollen (12.2%) and molds (7.4%) with p < 0.0001. A clear predominance of sensitization to the house dust mite Dermatophagoides pteronyssinus (77.8%) and Dermatophagoide s farinae (76.9%), in comparison to the other aeroallergens tested, in term s of sensitization (p = 0.00000) and papule size (p < 0.0002), was observed . The most highly sensitized group consisted of asthmatics between 5 and 15 years of age (D. pteronyssinus 90.7%, D. farinae 87.5%, dog hair 37.4%, ca t hair 43% grass pollen 15.9% and molds 9.9%). In the total study group, ma les were only more sensitive than females to D. pteronyssinus (82.1% vs. 71 .6%, p = 0.0009). We concluded that in the group of asthmatic children stud ied grass pollen showed a low capacity of sensitization, even though it is widely found all over our city The most sensitizing allergens were D, ptero nyssinus and D. farinae, followed by cat and dog hair.