Allergic Conjunctivitis: Causes and Symptoms

allergic is an inflammatory process affecting the conjunctiva induced by any allergen, be it a chemical substance (for example, solutions from contact lenses) or natural (for example, pollen).

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Probably, allergic conjunctivitis is the most common type I hypersensitivity reaction (IgE mediated allergies) affecting roughly 20% of total allergies.
Although a truly effective drug has not yet been identified to treat it, allergic conjunctivitis can be prevented by adopting specific precautionary measures of a hygienic-behavioral nature. To reduce the characteristic symptoms - such as itching, eye redness, light intolerance and eyelid swelling - antihistamines and / or corticosteroids (eye drops / ophthalmic ointments and tablets) are undoubtedly the most suitable.

Deepening

Being an allergic form, this type of conjunctivitis also represents an abnormal and exaggerated immune response of the organism to contact with an allergen.
The symptoms produced by allergic conjunctivitis begin after the "wrong recognition" of pollen, dust or other elements by the immune system, which identifies them as potentially dangerous substances for the organism.

The ferocious itching, profuse tearing and actual eyelid edema are due to the release of histamine and other vasoactive substances produced by mast cells located in the conjunctival. Taken together, these molecules stimulate the dilation of blood vessels and irritate the nerve endings; favored an overproduction of lacrimal secretion.

, gigantopapillary, from contact.

Classification of Allergic Conjunctivitis on the basis of onset Symptoms

First of all, two main forms of allergic conjunctivitis must be distinguished:

Acute: it is an urticarial form (causes symptoms such as urticaria and intense and ferocious itching) which is distinguished by an evident swelling of the eyelids. Symptoms usually subside within a relatively short time.
Chronic: the symptoms are less impetuous but tend to persist for long periods. At the conjunctival level, the patient complains of widespread itching, photophobia, redness and local irritation. When it is possible to isolate the allergen, it is essential to avoid contact as much as possible; if this is not possible, to reduce the symptoms it is advisable to use antihistamine and vasoconstrictor eye drops.

Classification of Allergic Conjunctivitis on the basis of the underlying cause

There are also other subtypes of allergic conjunctivitis, differentiated according to the causal agent (allergen) involved:

Seasonal allergic conjunctivitis: always associated with hay fever, this type of conjunctivitis finds its most plausible explanation in pollen allergy. It is characterized by transient episodes of hyperemia (eye redness), abundant tearing, eyelid edema. The cornea is not affected.
Perennial allergic conjunctivitis: the characteristic symptoms occur throughout the year, in response to different types of allergens, such as in particular, dust mites, pet epithelium (the so-called allergy to dog or cat hair) , molds, etc.
Atopic Allergic Conjunctivitis: Although relatively rare, this type of conjunctivitis is typical of young male adults. The disorder involves the eyelids that appear chapped, thickened and covered with small crusts. Generally, the allergy is not limited to the eye: the lateral folds of the neck and the antecubital cavity (small pit in the elbow joint) can also be involved.
Gigantopapillary allergic conjunctivitis: this is a "conjunctival allergy typical of contact lens or ocular prosthesis wearers. Asthma patients, hay fever patients or those who have a certain sensitivity to allergens of animal origin also have a rather high risk of developing gigantopapillary conjunctivitis. The characteristic symptoms of onset are: irritation, photophobia, itching, mucosepurulent secretions and intolerance to contact lenses.
Allergic contact dermatoconjunctivitis: it is essentially caused by a hypersensitivity reaction to some eye drops or to certain substances contained in a cosmetic. Generally, this form of conjunctivitis struggles to improve even with normal antihistamines. To prevent relapses, it is essential to avoid any possible contact with the allergen.

allergic conjunctivitis.