Conjunctivitis - Allergic, Seasonal & Perennial (Pediatric)

Allergic conjunctivitis in children is an inflammation of the conjunctiva triggered by exposure to allergens. Seasonal allergic conjunctivitis (SAC) occurs during specific pollen seasons, while perennial allergic conjunctivitis (PAC) occurs year-round due to persistent indoor allergens.

Definition

Epidemiology

Common in school-aged children and adolescents
Prevalence: up to 15–20% of children affected by allergic conjunctivitis
SAC peaks during spring and early summer due to pollen exposure
PAC persists throughout the year, often linked to dust mites, pet dander, or mold
Family history of atopy increases risk

Etiology

IgE-mediated hypersensitivity reaction to environmental allergens
Common allergens: pollens, dust mites, animal dander, molds
Genetic predisposition to atopy
Exposure to irritants like smoke or strong odors can exacerbate symptoms
Triggers vary with geography and season

Pathophysiology

Allergen exposure triggers IgE-mediated mast cell degranulation
Release of histamine and inflammatory mediators leads to vasodilation, edema, and itching
Recruitment of eosinophils amplifies inflammation
Chronic exposure can cause conjunctival thickening and papillary reaction
Tear film instability may worsen ocular surface irritation
Repeated inflammation can increase risk of keratopathy in severe cases