What is the initial treatment approach for a patient presenting with conjunctivitis?

Initial Treatment Approach for Conjunctivitis

The initial treatment depends entirely on determining the etiology through discharge character, symptom pattern, and exposure history—bacterial conjunctivitis receives topical broad-spectrum antibiotics (moxifloxacin 0.5% three times daily for 5-7 days), viral conjunctivitis receives only supportive care with artificial tears and cold compresses, and allergic conjunctivitis receives topical antihistamines with mast cell-stabilizing activity. 1, 2

Diagnostic Algorithm to Guide Treatment

History Elements That Differentiate Etiology

Bacterial conjunctivitis indicators:

• Mucopurulent or purulent discharge with eyelids matted shut upon waking 1, 3
• Absence of itching 4
• Unilateral or bilateral presentation 2
• Recent contact with infected individuals in school/daycare settings 1

Viral conjunctivitis indicators:

• Watery discharge with preauricular lymphadenopathy 1, 3
• Recent upper respiratory infection or exposure to infected individuals 1
• Follicular reaction on conjunctival examination 1

Allergic conjunctivitis indicators:

• Severe itching as the predominant symptom 1, 4
• Bilateral presentation with mucoid discharge 5
• History of atopy, allergic rhinitis, or asthma 2
• Seasonal pattern or allergen exposure 1

Physical Examination Requirements

Measure visual acuity, perform external examination for preauricular lymphadenopathy, and conduct slit-lamp biomicroscopy to evaluate conjunctival injection pattern, discharge character, and corneal clarity. 1, 6

Treatment by Etiology

Bacterial Conjunctivitis

For mild to moderate bacterial conjunctivitis:

• Apply topical moxifloxacin 0.5% three times daily for 5-7 days directly into the conjunctival sac 1, 2
• Moxifloxacin provides superior gram-positive coverage including activity against some MRSA strains, with clinical cure rates of 66-69% by day 5-6 and microbiological eradication rates of 84-94% 2, 7
• Alternative fluoroquinolones include levofloxacin, gatifloxacin, ciprofloxacin, or besifloxacin if moxifloxacin is unavailable 1, 2

For severe bacterial conjunctivitis with copious purulent discharge:

• Obtain conjunctival cultures and Gram staining before initiating treatment, especially if gonococcal infection or MRSA is suspected 8, 1
• Consider compounded topical vancomycin if MRSA is suspected and patient fails to respond to fluoroquinolones within 48-72 hours 2

Critical pitfall: Gonococcal and chlamydial conjunctivitis require systemic antibiotics—topical therapy alone is insufficient. 8, 1 For gonococcal conjunctivitis in adults, administer ceftriaxone 250 mg IM single dose plus azithromycin 1 g oral single dose. 1 For chlamydial conjunctivitis in adults, administer azithromycin 1 g oral single dose or doxycycline 100 mg oral twice daily for 7 days. 8, 1

Viral Conjunctivitis

For adenoviral conjunctivitis (most common):

• Provide supportive care only with refrigerated preservative-free artificial tears four times daily and cold compresses 1, 2
• Never prescribe topical antibiotics—they provide no benefit and contribute to antibiotic resistance 1, 2
• Counsel on strict hand hygiene with soap and water to prevent transmission 1, 2
• Advise avoiding close contact for 7-14 days from symptom onset 2

For HSV conjunctivitis:

• Apply topical ganciclovir 0.15% gel three to five times daily or topical trifluridine 1% solution five to eight times daily 1, 2
• Add oral antivirals (acyclovir, valacyclovir, or famciclovir) 1, 2
• Never use topical corticosteroids without antiviral coverage—they potentiate HSV infection and worsen outcomes 1, 2

Critical pitfall: Topical corticosteroids may be considered only in severe adenoviral cases with marked chemosis, severe lid swelling, epithelial sloughing, or membranous conjunctivitis, but require close monitoring for elevated intraocular pressure and cataract formation. 2 Most adenoviral conjunctivitis does not require steroids. 2

Allergic Conjunctivitis

First-line treatment:

• Topical antihistamines with mast cell-stabilizing activity (second-generation agents) applied as directed 1, 2
• Adjunctive measures include cold compresses, refrigerated preservative-free artificial tears, and sunglasses as an allergen barrier 2

Second-line treatment if symptoms persist:

• Add a brief 1-2 week course of low side-effect profile topical corticosteroids with monitoring of intraocular pressure 2

Critical pitfall: Avoid chronic use of topical vasoconstrictors—they cause rebound vasodilation. 2 Oral antihistamines may worsen dry eye syndrome and exacerbate allergic conjunctivitis. 2

Red Flags Requiring Immediate Ophthalmology Referral

Refer immediately for any of the following: 8, 1

• Visual loss or decreased vision
• Moderate or severe pain
• Severe purulent discharge suggesting gonococcal infection
• Corneal involvement (infiltrate, ulcer, or opacity)
• Conjunctival scarring
• Lack of response to therapy after 3-4 days
• Recurrent episodes
• History of HSV eye disease
• Immunocompromised status
• Neonatal conjunctivitis (requires systemic treatment coordinated with pediatrician)
• Contact lens wear with conjunctivitis
• Recent ocular surgery
• Vesicular rash on eyelids or nose

Follow-Up Protocol

For bacterial conjunctivitis:

• Advise return in 3-4 days if no improvement 8, 1
• Signs of positive response include reduced pain and discharge, lessened eyelid edema or conjunctival injection 2

For gonococcal conjunctivitis:

• Daily visits until resolution are mandatory—delayed referral leads to poor outcomes including corneal perforation and vision loss 1, 2

For chlamydial conjunctivitis:

• Re-evaluate following treatment completion due to treatment failure rates up to 19% 8
• Treat sexual contacts simultaneously and screen for concurrent genital infections 8, 1
• Consider sexual abuse in children with gonococcal or chlamydial conjunctivitis 8, 1

Special Populations

Neonates:

• Systemic therapy is mandatory for chlamydial conjunctivitis because more than 50% of infants have concurrent infection at other sites (nasopharynx, genital tract, lungs) 8, 1
• Erythromycin base or ethylsuccinate 50 mg/kg/day oral divided into 4 doses for 14 days for chlamydial conjunctivitis 1
• Ceftriaxone 25-50 mg/kg IV or IM single dose for gonococcal conjunctivitis 1
• Monitor infants receiving erythromycin for signs of infantile hypertrophic pyloric stenosis 2

Contact lens wearers:

• Immediate ophthalmology referral is required due to risk of bacterial keratitis 1