Treatment of Conjunctivitis
Determine the Etiology First - Treatment Depends Entirely on the Cause
The treatment of conjunctivitis is fundamentally different based on whether it is viral, bacterial, or allergic, and using the wrong treatment can cause harm. 1
Key Clinical Differentiators
Viral conjunctivitis presents with:
- Watery discharge (not purulent) 1
- Follicular reaction on inferior tarsal conjunctiva 1
- Preauricular lymphadenopathy 1
- Often starts unilateral but becomes sequentially bilateral 1
- Concurrent upper respiratory infection common 1
Bacterial conjunctivitis presents with:
- Mucopurulent discharge with matted eyelids on waking 1, 2
- Papillary (not follicular) reaction 1
- Lack of itching 2
- May be unilateral or bilateral 1
Allergic conjunctivitis presents with:
- Itching as the most consistent and distinguishing feature 1
- Bilateral presentation 1
- Watery discharge with mild mucous component 1
- History of atopy, asthma, or eczema 1
- No preauricular lymphadenopathy 1
Treatment Algorithm by Etiology
Viral Conjunctivitis - Supportive Care Only
Do NOT use antibiotics for viral conjunctivitis - they provide no benefit and cause unnecessary toxicity. 1, 3
Treatment consists of:
- Refrigerated preservative-free artificial tears 4 times daily 1, 3
- Cold compresses for symptomatic relief 1, 3
- Topical antihistamines for itching relief (not antivirals) 1
- Patient education about high contagiousness - minimize contact with others for 10-14 days 1
- Strict hand hygiene with soap and water 1, 4
Special considerations:
- Most cases are self-limited, resolving within 5-14 days 1
- For severe cases with marked chemosis, lid swelling, or membranous conjunctivitis, topical corticosteroids may be considered BUT require close ophthalmology follow-up for monitoring intraocular pressure and cataracts 1, 3
- HSV conjunctivitis requires topical ganciclovir 0.15% gel or trifluridine 1% solution PLUS oral antivirals (acyclovir, valacyclovir, or famciclovir) 3
- Never use corticosteroids in HSV conjunctivitis without antiviral coverage - this potentiates viral replication and can cause corneal perforation 1, 3
Bacterial Conjunctivitis - Antibiotics for Moderate-Severe Cases
Mild bacterial conjunctivitis is self-limited and may resolve without treatment, but topical antibiotics shorten duration and allow earlier return to work/school. 1, 2
For moderate to severe bacterial conjunctivitis, use a 5-7 day course of broad-spectrum topical antibiotic: 1
First-line choice: Moxifloxacin 0.5% ophthalmic solution
- Dosing: 1 drop in affected eye 3 times daily for 7 days 5
- Superior gram-positive coverage including some MRSA strains 3
- 81% complete resolution rate at 48 hours 3
- No single antibiotic has proven superiority, so choice can be based on convenience and cost 1, 3
Alternative topical options if fluoroquinolones unavailable:
- Erythromycin ointment 1
- Polymyxin B/trimethoprim drops 1
- Gentamicin 3
- Ofloxacin 0.3% four times daily 3
Critical exceptions requiring systemic antibiotics:
Gonococcal conjunctivitis:
- Presents with marked lid edema, severe purulent discharge, preauricular lymphadenopathy 1
- Requires ceftriaxone 250 mg IM single dose PLUS azithromycin 1 g oral single dose 3
- Daily follow-up until resolution mandatory 4
- Can cause corneal perforation if untreated 1, 4
- Hospitalization may be necessary 4
- Treat sexual contacts concurrently 4
Chlamydial conjunctivitis:
- Requires azithromycin 1 g oral single dose OR doxycycline 100 mg oral twice daily for 7 days 3
- Topical therapy alone is inadequate 1
- More than 50% of infants have infection at other sites 4, 3
- Treat sexual contacts concurrently 4
- Consider sexual abuse in children 4, 3
Follow-up: Return if no improvement after 3-4 days of treatment 4
Allergic Conjunctivitis - Antihistamines and Mast Cell Stabilizers
First-line treatment: Topical antihistamines with mast cell-stabilizing activity 1, 4
- Options include olopatadine or ketotifen 1
- These are more effective than oral antihistamines for ocular symptoms 1
Adjunctive measures:
- Wear sunglasses as barrier to airborne allergens 1, 4
- Cold compresses 1, 4
- Refrigerated artificial tears 1
- Avoid eye rubbing 1
- Identify and avoid allergen triggers 3
For persistent or severe cases:
- Mast cell stabilizers for recurrent cases 4
- Brief 1-2 week course of low side-effect profile topical corticosteroids (fluorometholone, rimexolone, or loteprednol) with monitoring of intraocular pressure 1, 4
- Consider allergen-specific immunotherapy, especially in children 1
Red Flags Requiring IMMEDIATE Ophthalmology Referral
Refer urgently if ANY of the following are present: 1, 4
- Visual loss or decreased vision
- Moderate or severe pain
- Severe purulent discharge
- Corneal involvement (fluorescein staining shows epithelial defects)
- Conjunctival scarring
- Lack of response to therapy after 3-4 days
- Recurrent episodes
- History of HSV eye disease
- Immunocompromised state
- Suspected gonococcal or chlamydial infection
- Neonatal conjunctivitis (requires hospitalization for parenteral therapy) 1, 4
Critical Pitfalls to Avoid
Do not use antibiotics indiscriminately for viral conjunctivitis - this contributes to resistance and causes unnecessary toxicity 1, 3
Do not use topical corticosteroids without close ophthalmology follow-up - they can prolong adenoviral infections, worsen HSV infections, cause elevated intraocular pressure, and cataracts 1, 3
Do not miss gonococcal conjunctivitis - it requires immediate systemic treatment and can cause corneal perforation 1, 4
Do not use topical therapy alone for chlamydial or gonococcal conjunctivitis - systemic antibiotics are mandatory 1, 4, 3
Avoid contact lens wear during any form of infectious conjunctivitis 1
Consider sexual abuse in children with sexually transmitted conjunctivitis - this mandates appropriate reporting 4, 3