Treatment of Conjunctivitis
The treatment of conjunctivitis depends entirely on the underlying etiology: viral conjunctivitis requires only supportive care without antibiotics, bacterial conjunctivitis may benefit from topical antibiotics in moderate-to-severe cases, and allergic conjunctivitis responds to topical antihistamines with mast cell-stabilizing activity. 1, 2, 3
Immediate Assessment: Rule Out Red Flags Requiring Ophthalmology Referral
Before initiating treatment, assess for the following conditions that mandate immediate ophthalmology consultation: 2, 3
- Visual loss or decreased vision 2, 3
- Moderate or severe pain (suggests keratitis, uveitis, or acute angle-closure glaucoma) 2, 3
- Severe purulent discharge 2, 3
- Corneal involvement (check with fluorescein staining) 2, 3
- Conjunctival scarring 2, 3
- History of herpes simplex virus eye disease 2, 3
- Immunocompromised state 2, 3
- Recurrent episodes 2, 3
- Lack of response to therapy after 3-4 days 3
Determine the Etiology Based on Clinical Features
Viral Conjunctivitis
- Watery discharge with follicular reaction on inferior tarsal conjunctiva 2
- Preauricular lymphadenopathy 2, 3
- Often abrupt onset, initially unilateral but becomes sequentially bilateral 2
- May have concurrent upper respiratory infection 2
- Subconjunctival hemorrhages, chemosis, eyelid swelling common 2
Bacterial Conjunctivitis
- Mucopurulent discharge with matted eyelids upon waking 2, 4
- Papillary rather than follicular reaction 2
- Lack of itching and absence of prior conjunctivitis history 4
- May have concurrent otitis media, sinusitis, or pharyngitis in children 2
Allergic Conjunctivitis
- Itching is the most consistent and distinguishing feature 2, 4
- Bilateral presentation with watery discharge 2
- Often seasonal or perennial pattern 2
- No preauricular lymphadenopathy or matted eyelids 2
- May have concurrent allergic rhinitis or asthma 2
Treatment Algorithm by Etiology
Viral Conjunctivitis: Supportive Care Only
Avoid antibiotics entirely—they provide no benefit and may cause toxicity. 2, 3
Supportive measures include: 2, 3, 5
- Artificial tears (preferably refrigerated and preservative-free) for symptomatic relief 2, 5
- Cold compresses 2, 5
- Topical antihistamines for symptomatic relief 2, 3
- Patient education about contagiousness: minimize contact with others for 10-14 days from symptom onset 2
- Strict hand hygiene with soap and water 2, 3
- Avoid sharing towels, pillows, or cosmetics 3
Critical pitfall: Topical corticosteroids should be avoided in most cases, as they can prolong adenoviral infections, worsen HSV infections, and cause increased intraocular pressure and cataracts. 2, 3 If severe cases with marked chemosis and lid swelling require corticosteroids, this necessitates close ophthalmology follow-up with regular IOP monitoring. 2, 3
Follow-up: Patients should return if symptoms persist beyond 2-3 weeks or worsen. 2
Bacterial Conjunctivitis: Selective Antibiotic Use
Mild bacterial conjunctivitis is self-limited and may resolve without antibiotics, but topical antibiotics can shorten the duration of infection. 2, 4, 6
For moderate-to-severe bacterial conjunctivitis: 2, 3
- Prescribe a 5-7 day course of broad-spectrum topical antibiotic 2, 3
- No specific antibiotic has proven superiority—choose the most convenient or least expensive option 2
- Common options include polymyxin-bacitracin 7, 6 or erythromycin 8
- Dosing: Apply ointment 1-3 times daily for bacitracin 7 or up to 6 times daily for erythromycin depending on severity 8
Special considerations requiring systemic therapy: 2, 3
- Gonococcal conjunctivitis: Requires immediate systemic antibiotics plus topical therapy; hospitalization may be necessary; can cause corneal perforation 2, 3
- Chlamydial conjunctivitis: Requires systemic antibiotics (topical therapy alone is inadequate); treat sexual contacts concurrently 2, 3, 8
- Contact lens wearers: Always treat with antibiotics and refer to ophthalmology to evaluate for corneal ulcers 2, 9
Follow-up: Patients should return if no improvement after 3-4 days of treatment. 3
Critical pitfall: In children with sexually transmitted conjunctivitis, consider child abuse and make appropriate reports. 2
Allergic Conjunctivitis: Antihistamines and Environmental Modifications
Topical antihistamines with mast cell-stabilizing activity are first-line treatment. 1, 2, 3, 4
Environmental modifications: 1, 3
- Wear sunglasses as barriers to airborne allergens 1, 3
- Use cold compresses and refrigerated artificial tears 1, 3
- Avoid eye rubbing 1
- Hypoallergenic bedding, frequent clothes washing, bathing before bedtime 1
- First-line: Topical antihistamines with mast cell-stabilizing properties (e.g., olopatadine, ketotifen) 1, 2
- For persistent/recurrent cases: Mast cell stabilizers 1, 3
- For severe cases not adequately controlled: Brief course (1-2 weeks) of topical corticosteroids with low side-effect profile 1, 2
- Oral antihistamines may be used but are less effective than topical agents and may worsen dry eye 1, 2
Critical pitfall: Chronic use of vasoconstrictor agents can cause rebound vasodilation. 1, 2 Punctal plugs should be avoided as they prevent flushing of allergens. 1
For refractory cases: Consider referral to allergist for allergen-specific immunotherapy. 1, 2
Infection Control for All Infectious Conjunctivitis
- Hand washing is the single most important preventive measure 3
- Disinfect surfaces with EPA-registered hospital disinfectant or 1:10 dilution of household bleach 2, 3
- Discontinue contact lens wear during any infectious conjunctivitis 2
- Avoid sharing personal items 3
Monitoring for Patients on Topical Corticosteroids
If corticosteroids are prescribed (only for severe allergic or vernal conjunctivitis under ophthalmology guidance): 1, 2