How do I prevent allergies?

That feeling of discomfort and irritation that causes you to rub your eye as if something is in it
when there is nothing, could be allergic reaction and it’s called allergic conjunctivitis
It is an inflammation of the ocular surface in response to a transient allergen (e.g. pollen in
seasonal allergic conjunctivitis), or a persistent allergen (e.g. house dust mite in perennial allergic
conjunctivitis).
 Seasonal allergic conjunctivitis (SAC) is a type I hypersensitivity response with
conjunctival activated mast cells as a direct result of allergen cross-linking of surface IgE
receptors resulting in degranulation and release of histamine, leukotrienes, proteases,
prostaglandins, cytokines, and chemokines. All these substances induce vascular leakage,
resulting in further cellular infiltration of eosinophils and neutrophils and edema but little
or no T-cell infiltration is observed.
 In perennial allergic conjunctivitis (PAC), the conjunctival tissue is infiltrated by
eosinophils, neutrophils, and a small number of T cells, probably recruited as a result of
the release of chemokines that attract these cells to the site of inflammation.
 Symptoms
 redness
 watering
 discharge
 discomfort or eye pain
 ocular itching
 Visual disturbance is usually minimal except in the more severe disorders and patients may
also complain of swelling of the lids.

 Many patients with allergic conjunctivitis will have a history of current or previous non-
ocular allergic or atopic conditions (eczema, asthma, urticaria, rhinitis).

 Classic ocular signs:
 lid swelling,
 diffuse conjunctival redness,

 mild swelling,
 often combined to give a pink rather than red color,
 Velvety thickening and redness of the tarsal conjunctiva with the presence of fine
excrescences called papillae, which may vary from tiny pinprick size to giant papillae
which are >1 mm in diameter and give a cobblestone appearance under the lid.
 Macroscopic noticeable swelling of the conjunctiva, called ‘chemosis’, is sometimes seen.
 Other signs, such as dermatitis of the lid skin,
inflammation of the lid margin (blepharitis),
 conjunctival scarring, a

 Pale-pink coloration in an annular pattern or with characteristic white dots called Horner-
Trantas dots.

o Treatment
 Oral antihistamines
 Topical mast cell inhibitors
 Anti-allergies