Objective: To analyze the clinical characteristics of Chenopodiaceae pollen induced seasonal allergic rhinitis (SAR) as well as the distribution and sensitization characteristics of Chenopodiaceae pollen in Inner Mongolia grassland of northern China. Methods: From May 2015 to August 2015, using stratified, cluster and random sampling, a field interviewer-administered survey study and skin prick test (SPT) were conducted in six areas of Inner Mongolia grassland (Xilinhot, Erenhot, Duolun, Tongliao, Jarud, Kailu), and pollen monitoring was carried out in the above six areas from January 1 to December 31 of 2015. The clinical characteristics of Chenopodiaceae pollen induced SAR, distribution and sensitization characteristics of Chenopodiaceae pollen in these regions were observed. SAS software 9.4 was used for data processing. Results: A total of 6 043 subjects completed the study. The prevalence of Chenopodiaceae pollen induced SAR was 13.2% (795/6 043). The highest prevalence was found in the 18-39 age group. Subjects from urban areas showed higher prevalence of SAR than rural areas (61.2% vs 37.9%, P<0.001). There was significant regional difference in the prevalence rate of Chenopodiaceae pollen induced SAR among the above six areas (Xilinhot 21.5%, Erenhot 17.8%, Duolun 8.9%, Tongliao 6.9%, Jarud 15.3%, Kailu 9.7%, P<0.001). The main clinical symptoms of Chenopodiaceae pollen induced SAR were sneezing (96.5%) and nasal itching (92.2%). Eye itching was more obvious among the ocular symptoms (69.1%), while fatigue (32.1%) and drowsiness (31.5%) were more prominent among other related symptoms. Among comorbidities of Chenopodiaceae pollen induced SAR, allergic conjunctivitis accounted for 71.4% (568/795), food allergy accounted for 86.7% (689/795) and asthma accounted for 16.7% (133/795). The peak of Chenopodiaceae pollen spread was in August. The prevalence of Chenopodiaceae pollen induced SAR was positively correlated with the concentration of Chenopodiaceae pollen (R²=0.78, P=0.043). The SPT positive rate of Chenopodiaceae pollen was 21.2% (1 282/6 043), and Xilinhot had the highest rate in six regions (28.0%, 236/842). Conclusions: The prevalence of Chenopodiaceae pollen induced SAR in Inner Mongolia grassland stays at a high level. Sneezing is the most obvious symptom of SAR. The peak of Chenopodiaceae pollen spread is in August and the prevalence of Chenopodiaceae pollen induced SAR is positively correlated with the pollen concentration.
Allergens ; Chenopodiaceae ; China/epidemiology* ; Grassland ; Humans ; Pollen ; Rhinitis, Allergic, Seasonal/epidemiology*

Objective: To investigate the self-reported prevalence, clinical characteristics, complications of allergic rhinitis (AR) and the sensitization of outdoor air pollen allergens in children in the Inner mongolia grassland region. Methods: A multistage, stratified and random clustered sampling with a face-to-face interview survey study in children from 0 to 17 years old was performed together with 10 common allergen skin prick tests (SPT) and measurements of the daily pollen count in 6 regions in the Inner mongolia grassland region from May to August of 2015. SAS 9.4 software was used for data analysis. Results: A total of 2 443 subjects completed the study. The self-reported prevalence of AR was 26.6%. The prevalence of boys was higher than that of girls (28.8% vs 24.3%, χ²=6.157, P<0.05). Subjects from urban areas showed higher prevalence than rural areas (34.7% vs 18.8%, χ²=79.107, P<0.05). There was significant regional difference in the prevalence of AR among the six areas investigated (χ²=221.416, P<0.05). The main clinical symptoms of AR were sneezing (88.2%) and nasal congestion (78.6%). Among combined diseases, asthma accounted for 16.5% (107/650), rhinoconjunctivitis accounted for 47.9% (311/650). The peak season of AR was April and July, with the top SPT positive allergens of Artemisia species and chenopodium in this area. Conclusions The prevalence AR in children in the Inner mongolia grassland region is extremely high. Sneezing is the main clinical symptom. Rhinoconjunctivitis is the most common combined disease. High summer and autumn pollen exposure is the main cause of AR.