Allergic conjunctivitis Allergic conjunctivitis Allergic conjunctivitis is inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist of redness (mainly due to vasodilation of the peripheral small blood vessels), edema (swelling) of the conjunctiva, itching, and increased lacrimation (production of tears). If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis. The symptoms are due to release of histamine and other active substances by mast cells, which stimulate dilation of blood vessels, irritate nerve endings, and increase secretion of tears.
Balsam of Peru listed by its name by mandatory labeling conventions. It can cause allergic reactions, with numerous large surveys identifying it as being in the "top five" allergens most commonly causing patch test reactions. It may cause inflammation, redness, swelling, soreness, itching, and blisters, including allergic contact dermatitis, stomatitis (inflammation and soreness of the mouth or tongue), cheilitis (inflammation, rash, or painful erosion of the lips, oropharyngeal mucosa, or angles of their mouth), pruritus, hand eczema, generalized or resistant plantar dermatitis, rhinitis, and conjunctivitis. Balsam of Peru is an aromatic viscous resin obtained by scorching or inflicting V-shaped wounds on the bark