Initial assessment
When assessing a child with a red eye and suspected acute conjunctivitis, the first step is to exclude warning signs. Although most cases of conjunctivitis in children are benign and self-limiting, some symptoms may indicate potentially serious ocular disease.
The presence of severe eye pain, marked photophobia, reduced visual acuity, proptosis, restricted ocular motility, significant eyelid swelling or corneal opacity should prompt urgent referral. These findings are not consistent with simple conjunctivitis and require consideration of alternative diagnoses such as keratitis, uveitis, corneal ulcer or orbital cellulitis.
Once these severity criteria have been excluded, the assessment should focus on the characteristics of the ocular discharge, associated symptoms, laterality and clinical context.
Viral conjunctivitis
Viral conjunctivitis is the most common cause of conjunctivitis in children. It typically presents with serous or watery discharge, tearing and conjunctival redness. It is often associated with an upper respiratory tract infection, fever, tonsillitis or preauricular lymphadenopathy.
In many cases, it begins in one eye and becomes bilateral within 24–48 hours, which may create diagnostic uncertainty. Treatment is mainly supportive and includes saline irrigation, cold compresses, artificial tears and reinforcement of hygiene measures.
Topical antibiotics are not routinely indicated.
Bacterial conjunctivitis
The presence of persistent mucopurulent discharge, frequent need for ocular cleaning and eyelids stuck together on waking increases the likelihood of bacterial conjunctivitis.
Although many cases are self-limiting, more severe or persistent presentations may benefit from topical treatment. Available options include local antibiotics, usually combined with ocular hygiene measures and saline irrigation.
It is important to remember that initial unilateral involvement does not reliably distinguish a bacterial cause, as some cases of viral conjunctivitis may also begin in one eye.
Allergic conjunctivitis
In allergic conjunctivitis, the most characteristic clinical feature is intense ocular itching. It is usually bilateral and may be associated with tearing, conjunctival swelling and a personal history of atopy, rhinitis or seasonal allergy.
Treatment includes allergen avoidance, artificial tears and topical antihistamines such as olopatadine or ketotifen.
Neonatal conjunctivitis
Conjunctivitis in newborns requires particular attention because some causes may be associated with significant complications.
The timing of symptom onset may help guide the diagnosis. Chemical conjunctivitis may occur within the first 24–48 hours; gonococcal infection should be considered between days 2 and 5; later onset increases the likelihood of other bacterial causes or infection with Chlamydia trachomatis.
These situations require specific assessment and management.
Differential diagnoses
Not every red eye is caused by conjunctivitis. Potentially serious differential diagnoses should be considered, including ocular foreign body, keratitis, uveitis, glaucoma and orbital cellulitis.
An integrated interpretation of symptoms, clinical signs and the context of presentation is essential to prevent diagnostic delay.
Practical approach
In practical terms, the assessment of pediatric conjunctivitis follows a simple sequence: exclude signs of severity, identify the most likely etiology and select the appropriate treatment.
A structured approach helps reduce unnecessary antibiotic use, improve clinical management and support the early recognition of conditions requiring urgent assessment.
