Allergic conjunctivitis: This is often the most common cause of eye discharge in children, characterized by itchy, red, and watery eyes, especially during allergy seasons or in children with known allergies.

Viral conjunctivitis: Common in children, it presents with redness, itching, and a watery discharge, often accompanied by upper respiratory symptoms.
Bacterial conjunctivitis: Typically presents with a thicker, more purulent discharge, and can be associated with eyelid swelling and redness.
Blepharitis: Inflammation of the eyelids can cause eye discharge, especially in the morning, along with eyelid redness and swelling.

Gonococcal conjunctivitis: Although less common, it's critical to consider in neonates (as a result of maternal transmission during birth) or in sexually abused children, presenting with severe, purulent conjunctivitis.
Herpes simplex keratitis: Can cause eye discharge along with pain, redness, and vision changes. It's a serious condition that requires prompt treatment to prevent complications.
Chlamydial conjunctivitis: In neonates, this can be a result of maternal transmission during birth, leading to inclusion conjunctivitis, which can become chronic if not treated.

Kawasaki disease: Although rare, it can present with bilateral nonexudative conjunctival injection among other systemic symptoms like fever, rash, and lymphadenopathy.
Sjögren's syndrome: An autoimmune disorder that can cause dry eyes and sometimes a sensation of discharge, though it's exceedingly rare in children.
Dacryocystitis: Infection or inflammation of the lacrimal sac, which can cause persistent discharge, especially if there's an underlying anatomical issue like nasolacrimal duct obstruction.