Allergic conjunctivitis is one of the most common disorders of the external eye. Hypersensitivity of the conjunctiva to foreign substances is characterized by discharge, redness, itching, irritation, swelling, light sensitivity, and tearing. The tear fluid contains a small amount of eosinophils and histamine. Allergic eye conditions can be classified into four categories. They are hay fever conjunctivitis, vernal conjunctivitis, atopic keratoconjunctivitis, and giant papillary conjunctivitis.
过敏性结膜炎是最常见的外眼疾病之一。结膜对外来物质的超敏反应表现为分泌物增多、发红、瘙痒、刺激感、肿胀、畏光和流泪。泪液中含有少量嗜酸性粒细胞和组胺。过敏性眼部疾病可分为四类。它们是花粉症结膜炎、春季结膜炎、特应性角结膜炎和巨乳头性结膜炎。
