allergen [ˈælərdʒən]

例句:

• Tobacco smoke isn't an allergen but it aggravates asthma and nasal allergies.
  来自BBC
• Objective To find out the common allergen of abnormal rhinitis in Shenzhen.
  目的了解深圳地区变应性鼻炎的常见变应原.
  
• To investigate the allergen distribution and characteristic in hypersensitive children.
  了解儿童变态反应性疾病患者过敏原分布情况及特点.
  
• When the immune system encounters an allergen , it may become sensitised.
  当免疫系统发现了过敏原就会致敏.
  
• Scientists at Leatherhead Food International measured latex allergen levels in 21 types of food packaging.
  来自BBC
• Once an allergen has been identified, practical steps can be taken to avoid it.
  来自BBC