Conjunctivitis%20-%20allergic,%20seasonal%20-and-%20perennial Signs and Symptoms

• A classic type 1 immunoglobulin E (IgE)-mediated hypersensitivity reaction wherein there is 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 and basophils may lead to the release of histamines that can cause capillary dilation and increased permeability and thus, conjunctival injection and swelling occur
  • Nerve endings are also stimulated causing pain and itching
• A recurrent condition that is often associated with allergic rhinitis, dry eye and meibomian gland dysfunction (MGD) with hyperproduction of mucin

• Also known as hay fever conjunctivitis 
• Most common form of allergic conjunctivitis in temperate climates
• Usually occurs and recurs at a certain period of the year (eg summer)
• Triggered by transitory allergens (eg tree or grass pollens)
• Subjectively more severe than PAC

Perennial Allergic Conjunctivitis (PAC)

• Manifests and recurs throughout the year with no seasonal predilection
• Most common in tropical climates
• House dust mites, animal dander and feathers are the major allergens implicated in PAC

• Eyelid edema, ocular/periocular itching with redness, tearing, burning, stinging, photophobia, watery or white stringy mucoid discharge, and/or ecchymosis (“allergic shiner”), foreign body sensation; characterized by exacerbations and remissions
  • Ocular itching is considered the cardinal symptom
  • Usually with bilateral involvement, although one eye may be more affected than the other
• Identify the date and timing of onset, and progress of symptoms
  • May be intermittent (<4 weeks) or persistent (>4 weeks)
• Symptoms tend to decrease with age