 From allergic rhinitis patients and healthy controls nasal mucus, nasal mucosa, and serum will be obtained. Nasal mucus will be collected with a special suction device equipped with a mucus trap from the middle meatus under endoscopic control without touching the mucosa. Nasal mucosa will be obtained through nasal brushes under local anesthesia and put into primary culture. Serum prepared from blood samples. Patients with grass or tree pollen allergy will be included and allergic state will be determined by skin prick tests and RAST Radio-Allergo-Sorbent-test. The aimed for sample size will be 15 patients per group. Samples will be obtained in and out of pollen season. Allergic patients will fill out a symptom score and samples will be taken when symptoms are strong in pollen season and disappeared out of pollen season. For healthy controls the time point of sample taking will be correlated to the allergic rhinitis patients to have a similar pollen exposure. Nasal mucus will be sent for Liquid Chromatography Tandem mass spectrometry for proteomic analysis and from nasal epithelial cells RNA will be isolated and send for Microarray analysis. By an integrative omics approach gene and protein expression will be correlated and cross talk between nasal mucus and epithelium will be analysed. The identification of key genes or gene clusters leads to further identification of key proteins or protein groups as biomarkers that could serve for novel therapeutic or diagnostic strategies in allergic rhinitis. The integrative omic approach downsizes the potential candidates since the focus lies on epithelial gene expression and their protein products and excludes proteins that are highly abundant without direct correlation to allergen exposure e.g. through plasma exudation. Moreover, the genomic and proteomic analysis could explain in more detail how the barrier of mucus and epithelium are affected by allergen exposure. The comparison to healthy controls and the longitudinal changes throughout the season further sheds light on how these individuals react upon allergen exposure and how this could lead to prevention of sensitization. 