Allergic Conjunctivitis: Review of Current Types, Treatments, and Trends.

Allergic conjunctivitis is an allergen-induced immune response secondary to the binding of immunoglobulin-E (IgE) to sensitized mast cells. Approximately 40% of North Americans and 20% of the world's population are impacted by some form of allergy and it continues to increase in prevalence, especially among children. Specified IgE antibodies can be found in almost all cases of exposure to seasonal or perennial allergens. Activation and degranulation of mast cells lead to increased tear levels of histamine, tryptase, leukotrienes, cytokines, and prostaglandins. The release of these factors initiates the recruitment of inflammatory cells in the conjunctival mucosa, which causes the late-phase reaction. Signs and symptoms of ocular allergies include itching, tearing, chemosis, and hyperemia, which can lead to decreased productivity and poor quality of life. Many treatment options are available to improve symptoms, including, mast cell stabilizers, antihistamines, dual-acting agents, steroids, nonsteroidal anti-inflammatory drugs (NSAIDS), and other off-label treatment modalities. This review article provides an overview of different types of allergic conjunctivitis, its pathology and immunology, and recommended methods of treatment.