Allergy is considered a systemic disease that manifests as one or more interrelated conditions. Among allergic manifestations can include: nasal allergies, chronic urticaria, eczema, allergic asthma, allergic oedematous laryngitis, ear and eye manifestations.
Allergic response consists of an unwanted and exaggerated reaction of the immune system to the action of a body or a body foreign substances (allergens) that it perceives it as a potential danger. It can be inherited or can be acquired throughout life by contact with different allergens.
This an allergen to the conjunctiva initiates two types of immune responses:
determined by the release of mediators "pre-formed" of inflammation (histamine and bradykinin is released from mast cells after exposure);
caused by arachidonic acid production and media conversion was "newly formed (prostaglandins, thromboxane, leucotrine that are issued 24 hours after exposure).
Mediators' pre-formed "stimulate nerve endings, causing itching, increase vascular permeability and cause vasodilation in the conjunctiva. The consequence of these mechanisms is the occurrence of hyperemia conjunctivitis (red eyes, watery, swollen).
Mediators' newly formed "emphasizes the above symptoms and maintain mechanisms similar action. If the first type of immune response occurs only in allergic reactions, the second can be triggered by local lesions (bacterial infection, trauma, surgery).
The main allergens involved in causing allergic reactions are eye dust and pollen.
Signs and symptoms of ocular allergy are: local pruritis (itching) and hyperemia conjunctivitis. It can be associated eyelid edema (swollen eyelids), erythema of the eyelid margin (margin red eyelids), papillary hyperplasia and hypertrophy (tarsal connective visible on slit lamp examination). This adenopathy (lymph) to the preauricular and submandibular we focused on one type of viral illness and do not run. Most often associated with ocular allergy seasonal allergies (allergic rhinitis, allergic bronchitis).
In the eye, simple allergic reactions typically produce a watery secretion (eye weep profusely), serous, nepurulenta and does not affect the cornea. When there is a purulent discharge from the agglutination of them in genes (eyes glued), a component suspected bacterial infection or otherwise. In cases with corneal involvement (when it appears blurred vision, photophobia, pain) associated with the emergence of a more consistent discharge orient us toward a more serious condition vernal keratoconjunctivitis. It is seen more frequently in warm climates. Onset is usually between 3-25 years, affected men are generally more common than that of women. The main clinical signs of spring keratoconjunctivitei, detected on clinical examination at the slit lamp are papillary hypertrophy of the tarsal conjunctiva upper-Trantas Horner points (white deposits - formed by gelatinous degeneration of the upper limbus directly involved in allergic eosinophils), areas of keratitis punctata superficial and, in severe cases, corneal ulcers.