Inter-Relationship between Rhinitis and Conjunctivitis in Allergic Rhinoconjunctivitis and Associated Risk Factors in Rural UK Children

ObjectiveAllergic conjunctivitis (AC) is a common condition, especially in childhood. The extent to which it occurs concurrently with or independently from allergic rhinitis (AR) has not been well described.AimTo examine the inter-relationship between rhinitis and conjunctivitis and the epidemiological risk factors for these conditions in a rural UK population.MethodsCross-sectional study of rural school children (aged 5–11 years). Parental questionnaires were used to diagnose allergic outcomes (including conjunctivitis, rhinitis and rhinoconjunctivitis), and to collect data on atopic history, demographic and environmental exposures. Odds ratios of allergic outcome by exposure were examined adjusted for age, sex, breastfeeding, family history of allergy, number of older and younger siblings.ResultsPrevalence of conjunctivitis was 17.5%, rhinitis 15.1% and rhinoconjunctivitis 13.0%. Seasonality of symptoms varied by condition: 64.7% of those with conjunctivitis had seasonal symptoms (April-Sept only), 46.7% of those with rhinitis and 92.2% of those with rhinoconjunctivitis. Living on a farm consistently reduced the risk of conjunctivitis (odds ratio 0.47, 95%CI 0.29–0.79, p = 0.004), rhinitis (OR 0.57, 95%CI 0.33–1.01, p = 0.05) and rhinoconjunctivitis (OR 0.57, 95%CI 0.32–1.03, p = 0.06). Exposure to farm animals (particularly in early life), current consumption of unpasteurised milk and playing in a barn or stable significantly reduced the risk of all three conditions.ConclusionMore children had parent-reported conjunctivitis than rhinitis. The majority of children with either condition also reported symptoms with the other condition. Farmers’ children have less eye and/or nasal symptoms. A number of farming variables linked with the farm microbial environment are likely to be mediating the protective effect.

研究背景：变应性结膜炎（Allergic conjunctivitis, AC）是一种常见病症，在儿童群体中尤为高发。目前学界对其与变应性鼻炎（Allergic rhinitis, AR）是合并发生还是独立发病的相关情况，尚未得到充分阐释。
研究目的：本研究旨在探究英国乡村人群中鼻炎与结膜炎的相互关联，以及这两种病症的流行病学危险因素。
研究方法：本研究为横断面研究，研究对象为英国乡村5~11岁的学龄儿童。研究采用家长填写的调查问卷对变应性相关病症（包括结膜炎、鼻炎及鼻结膜炎）进行诊断，并收集特应性病史、人口统计学特征及环境暴露相关数据。针对不同暴露因素下的变应性病症比值比进行分析，并对年龄、性别、母乳喂养情况、过敏家族史、长幼兄弟姐妹数量进行了校正。
研究结果：本次研究中，结膜炎的患病率为17.5%，鼻炎为15.1%，鼻结膜炎为13.0%。不同病症的症状季节性存在差异：64.7%的结膜炎患者仅在4~9月出现季节性症状，鼻炎患者中该比例为46.7%，而鼻结膜炎患者则高达92.2%。居住在农场可持续降低结膜炎的发病风险（比值比0.47，95%置信区间0.29~0.79，p=0.004）、鼻炎发病风险（比值比0.57，95%置信区间0.33~1.01，p=0.05）以及鼻结膜炎发病风险（比值比0.57，95%置信区间0.32~1.03，p=0.06）。接触农场动物（尤其是在生命早期）、当前饮用未巴氏杀菌牛奶，以及在谷仓或马厩中玩耍，均可显著降低上述三种病症的发病风险。
研究结论：家长报告的结膜炎患儿数量多于鼻炎患儿。多数同时患有其中一种病症的儿童，也会出现另一种病症的相关症状。农场儿童的眼部和/或鼻部症状更少。多项与农场微生物环境相关的农场暴露变量，可能是这种保护效应的介导因素。