conjunctivitis%20-%20allergic,%20seasonal%20-and-%20perennial
CONJUNCTIVITIS - ALLERGIC, SEASONAL & PERENNIAL

Conjunctivitis is the inflammation of the conjunctiva.

Allergic conjunctivitis happens when the direct exposure of the ocular mucosal surfaces to the environment causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells and basophils, leading to the release of histamines that causes capillary dilation and increased permeability and thus conjunctival injection and swelling.
Seasonal allergic conjunctivitis is the most common form of allergic conjunctivitis in temperate climates. It usually occurs and recurs at a certain period of the year (eg summer).
Perennial allergic conjunctivitis manifests and recurs throughout the year with no seasonal predilection. It is most common in tropical climates.

Introduction

Seasonal Allergic Conjunctivitis (SAC)
  • Most common form of allergic conjunctivitis in temperate climates
  • Usually occurs & recurs at a certain period of the year (eg summer)
  • Subjectively more severe than PAC

Perennial Allergic Conjunctivitis (PAC)

  • Manifests & recurs throughout the year with no seasonal predilection
  • Most common in tropical climates

Pathophysiology

  • Direct exposure of ocular mucosal surfaces to the environment that causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells & basophils, leading to the release of histamines that causes capillary dilation & increased permeability &, thus, conjunctival injection & swelling
    • Nerve endings are also stimulated causing pain & itching

Signs and Symptoms

  • Ocular/periocular itching with redness, tearing, burning, stinging, photophobia, watery discharge, &/or ecchymosis (“allergic shiner”), foreign body sensation; characterized by exacerbations & remissions
    • Itching is considered the cardinal symptom
    • Identify the date & timing of onset, & progress of symptoms
    • Symptoms tend to decrease with age
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