Allergic conjunctivitis and H1 antihistamines.

Allergic conjunctivitis is the most common form of ophthalmological allergy. Eye symptoms are one of the main and most frequent reasons for consultation among patients with allergic rhinoconjunctivitis, which in turn is the most common reason for visiting the allergologist, according to the Alergológica 2005 study. Itching is the key symptom of allergic conjunctivitis, and its relief is the principal objective of the broad range of treatment options available. Topical antihistamines with multiple actions (mast cell stabilization, and antiinflammatory and antihistaminic actions) are probably the best treatment option, thanks to their rapid action, safety and convenience of use. However, oral antihistamines (preferentially second generation drugs) can also play an important role, since they are of established efficacy and offer adequate treatment of the nasal symptoms that tend to accompany the ocular manifestations of allergic rhinoconjunctivitis. Models of allergic conjunctivitis are useful for investigational purposes and for advancing our knowledge of allergic reactions. Advances in the study of the physiopathology of ocular allergy allow us to introduce new therapeutic options for the management of such allergic reactions, thanks to the findings derived from models of this kind. The present review provides an update to the published data on allergic conjunctivitis and the current role of both topical and ocular antihistamines in treating the disorder.