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
Editor's Recommendations
Most Read Articles
Stephen Padilla, 4 days ago
Treatment with oral thrombopoietin receptor agonist eltrombopag leads to similar platelet counts in patients with chronic immune thrombocytopaenia (cITP) and persistent (per)ITP, according to the results of phase III (EXTEND) and IV studies presented at the 23rd Congress of the European Hematology Association (EHA 2018) held in Stockholm, Sweden.
Pearl Toh, 6 days ago
Lonely people were twice as likely to die from any cause than people who did not feel lonely, according to a study based on a national survey presented at the recent EuroHeartCare 2018 in Dublin, Ireland. Also, loneliness is associated with poorer patient-reported outcomes in terms of mental and physical health in patients with heart disease.
Jairia Dela Cruz, 4 days ago
A treatment regimen combining daratumumab plus bortezomib, melphalan and prednisone markedly extends progression-free survival in patients with multiple myeloma, inducing deep responses and demonstrating acceptable tolerability regardless of baseline renal function, according to the results of the phase III ALCYONE study.
2 days ago
Segmentectomy and lobectomy confer similar overall survival (OS) and lung cancer-specific survival (LCSS) among patients with primary nonsmall cell lung cancer (NSCLC) of ≤20 mm without lymph node or distant metastasis, a recent study has shown.