What is the recommended treatment for a patient with conjunctivitis, considering their medical history and potential causes such as bacterial or allergic reactions?

Treatment of Conjunctivitis

Initial Diagnostic Approach

The treatment of conjunctivitis depends entirely on identifying the underlying etiology—viral, bacterial, or allergic—through focused history and examination, as most cases can be managed without antibiotics. 1, 2

Critical Red Flags Requiring Immediate Ophthalmology Referral

Before initiating treatment, rule out vision-threatening conditions that require urgent specialist evaluation 2, 3:

• Visual loss or decreased vision 2
• Moderate to severe pain (suggests keratitis, uveitis, or acute angle-closure glaucoma) 2, 3
• Severe purulent discharge (concern for gonococcal infection) 2
• Corneal involvement on fluorescein staining 2, 3
• Conjunctival scarring 2
• History of herpes simplex virus eye disease 2, 3
• Immunocompromised state 2, 3
• Recent ocular surgery 4
• Lack of response to therapy after 3-4 days 2

Key Distinguishing Clinical Features

Viral conjunctivitis 1, 3:

• Watery discharge with abrupt onset 1
• Follicular reaction on inferior tarsal conjunctiva 1, 3
• Preauricular lymphadenopathy 3
• Often starts unilateral, becomes sequentially bilateral within days 1, 3
• Concurrent upper respiratory infection common 3

Bacterial conjunctivitis 1, 3:

• Mucopurulent discharge with matted eyelids on waking 1, 3
• Papillary (not follicular) reaction 1, 3
• Lack of itching 5
• May be unilateral or bilateral 3

Allergic conjunctivitis 1, 3:

• Itching is the most consistent and distinguishing feature 1, 5
• Bilateral presentation 3
• Watery discharge with mild mucous component 1
• Eyelid edema and periorbital hyperpigmentation 1
• History of atopy, asthma, or eczema 4

Treatment by Etiology

Viral Conjunctivitis

Viral conjunctivitis requires only supportive care, as it is self-limited and resolves within 5-14 days without antibiotics. 1, 2

Supportive measures 2, 3:

• Artificial tears for symptomatic relief 2, 3
• Cold compresses 2
• Topical antihistamines for symptomatic relief (not curative) 2, 3

Critical management points 2, 3:

• Avoid topical antibiotics entirely—they provide no benefit and may cause toxicity 2, 3
• Patient education about high contagiousness: minimize contact with others for 10-14 days from symptom onset 2
• Strict hand hygiene with soap and water 2, 6
• Avoid sharing towels, pillows, or cosmetics 2
• Disinfect surfaces with EPA-registered hospital disinfectant or 1:10 dilution of household bleach 2

Topical corticosteroids 2, 3:

• May be considered for severe cases with marked chemosis, lid swelling, or pseudomembranes 2, 3
• Require close ophthalmology follow-up for monitoring intraocular pressure and cataract formation 2, 3
• Use with extreme caution: may prolong viral shedding and worsen HSV infections 2, 3

Bacterial Conjunctivitis

Mild bacterial conjunctivitis is self-limited and resolves in 1-2 weeks without treatment, but topical antibiotics shorten disease duration and allow earlier return to school or work. 2, 5

Treatment approach 2, 3:

• For moderate to severe cases: 5-7 day course of broad-spectrum topical antibiotic 2, 3
• No specific antibiotic is superior—choose the most convenient or least expensive option 2, 3
• Options include erythromycin ointment, polymyxin B/trimethoprim drops, or fluoroquinolones (moxifloxacin 7, gatifloxacin 8) 2, 3
• Moxifloxacin: instill one drop in affected eye 3 times daily for 7 days 7
• Gatifloxacin: Day 1—one drop every 2 hours while awake (up to 8 times); Days 2-7—one drop 2-4 times daily 8

Follow-up 2:

• Patients should return for evaluation if no improvement after 3-4 days of treatment 2

Special high-risk bacterial forms requiring urgent treatment 2, 3:

Gonococcal conjunctivitis 2, 3:

• Marked eyelid edema, severe hyperpurulent discharge, rapid progression 1
• Requires systemic antibiotics in addition to topical therapy 2, 3
• Hospitalization may be necessary (mandatory for neonates) 2
• Daily follow-up until resolution 2
• Risk of corneal perforation 1, 3
• Treat sexual contacts concurrently 2

Chlamydial conjunctivitis 2, 3:

• Requires systemic antibiotic therapy—topical therapy alone is inadequate 2, 3
• More than 50% of infants may have infection at other sites 2
• Evaluate and treat sexual contacts 2, 3
• In low-to-middle income countries with limited antibiotic access, povidone-iodine 1.25% ophthalmic solution can be used 2

Contact lens-related conjunctivitis 5:

• Should be treated with antibiotics due to risk of serious complications 5
• Discontinue contact lens wear during any infectious conjunctivitis 2, 3

Allergic Conjunctivitis

Topical antihistamines with mast cell-stabilizing activity are first-line treatment for allergic conjunctivitis. 2, 3

Treatment algorithm 2, 3:

First-line therapy 2, 3:

• Topical antihistamines with mast cell-stabilizing activity (e.g., olopatadine, ketotifen) 2, 3
• Environmental modifications: wear sunglasses as barriers to airborne allergens 2, 3
• Cold compresses and refrigerated artificial tears 2, 3
• Avoid eye rubbing 3

Second-line for persistent/recurrent cases 2:

• Mast cell stabilizers 2

Third-line for severe cases 2, 3:

• Brief course (1-2 weeks) of topical corticosteroids with low side-effect profile 2, 3
• Loteprednol etabonate is a C-20 ester corticosteroid with improved safety profile—less likely to elevate intraocular pressure or cause cataracts compared to traditional ketone corticosteroids 9

Long-term management 3:

• Allergen-specific immunotherapy is beneficial, more so in children than adults 3
• Multidisciplinary approach with pediatricians, internists, and allergists 3

Common Pitfalls to Avoid

• Never use topical antibiotics indiscriminately for viral conjunctivitis—they cause unnecessary toxicity, contribute to resistance, and provide no benefit 2, 3
• Never use topical corticosteroids without close ophthalmology follow-up—risk of elevated intraocular pressure, cataract formation, prolonged adenoviral infections, and worsening HSV infections 2, 3
• Do not miss gonococcal conjunctivitis—it can cause corneal perforation and requires immediate systemic treatment 2, 3
• Avoid contact lens wear during any form of infectious conjunctivitis 2, 3
• Chronic and/or recalcitrant conjunctivitis may indicate underlying malignancy (sebaceous or squamous cell carcinoma) and requires further evaluation 2, 3
• In children with sexually transmitted conjunctivitis, consider and report child abuse 2
• Recognize dry eye and blepharitis as the most frequent causes of conjunctival inflammation—treat the underlying problem rather than the conjunctivitis itself 1