Treatment of Pink Eye (Conjunctivitis)
For mild bacterial conjunctivitis, prescribe a 5-7 day course of broad-spectrum topical antibiotic (such as polymyxin B/trimethoprim, erythromycin, or tobramycin) applied 4 times daily, which accelerates clinical remission and reduces transmissibility. 1
Determining the Type of Conjunctivitis
Bacterial Conjunctivitis
- Mucopurulent discharge with eyelids matted shut on waking is the hallmark presentation 1, 2
- Marked inflammation, lack of itching, and no history of prior conjunctivitis strongly suggest bacterial etiology 3, 4
- More common in children than adults 2
Viral Conjunctivitis
- Watery discharge with burning, gritty sensation 5, 2
- More common in adults 2
- Often self-limiting and requires only supportive care 3, 4
Allergic Conjunctivitis
- Bilateral itching is the most consistent sign 4
- Watery discharge without mattering 2
- Often seasonal presentation 5
Treatment Approach for Bacterial Conjunctivitis
Mild Cases
- Choose the most convenient or least expensive broad-spectrum topical antibiotic, as no clinical evidence suggests superiority of any particular agent 1
- Recommended options include:
- Topical antibiotics reduce symptom duration by days 2-5 and allow earlier return to school/work 1, 8
- While 41% of cases resolve spontaneously by days 6-10, antibiotics improve clinical remission rates (RR 1.21) and microbiological cure (RR 1.37) 9
Moderate to Severe Cases
- Obtain conjunctival cultures and Gram staining before initiating treatment, especially if copious purulent discharge, pain, and marked inflammation are present 1, 3
- Reserve fluoroquinolones (moxifloxacin, gatifloxacin, ofloxacin, ciprofloxacin) for moderate-to-severe cases or suspected resistant organisms 1, 3
- Contact lens wearers require fluoroquinolones due to higher risk of Pseudomonas infection 1
Special Bacterial Pathogens Requiring Systemic Therapy
- Gonococcal conjunctivitis requires systemic antibiotics (topical therapy alone is insufficient), plus saline lavage for comfort 1, 3
- Chlamydial conjunctivitis requires systemic antibiotics, especially in infants who may have infection at other sites 1, 3
- For MRSA infections, vancomycin may be required 1
Treatment for Viral Conjunctivitis
- Most cases are self-limiting and require only supportive care with artificial tears, cold compresses, and topical antihistamines 3, 4, 2
- Avoid topical antibiotics for viral conjunctivitis, as this promotes unnecessary costs and antibiotic resistance 1
- For herpes simplex virus conjunctivitis, topical antivirals may be beneficial 3
- For varicella zoster virus, topical antibiotics prevent secondary bacterial infection, and oral antivirals may help persistent disease 3
Treatment for Allergic Conjunctivitis
- Topical antihistamines with mast cell-stabilizing activity are the treatment of choice 4, 2
- Topical lubricants and systemic antihistamines are alternative options 5
Follow-Up and Red Flags
When to Schedule Follow-Up
- Advise patients to return if no improvement after 3-4 days of antibiotic treatment 1, 3
- Follow-up should include visual acuity measurement and slit-lamp biomicroscopy 1, 3
When to Refer to Ophthalmology
Immediate referral is indicated for: 1, 3
- Visual loss or moderate-to-severe pain
- Severe purulent discharge
- Corneal involvement or conjunctival scarring
- Lack of response to therapy or recurrent episodes
- Neonatal conjunctivitis (requires prompt consultation)
- Contact lens wearers (to evaluate for corneal ulcers) 5
Critical Pitfalls to Avoid
- Do not use topical corticosteroids unless under close ophthalmologic supervision, as they may prolong bacterial shedding and worsen infection 3
- If corticosteroids are used, perform baseline and periodic intraocular pressure measurements to monitor for glaucoma 10
- Consider sexual abuse in children with gonococcal or chlamydial conjunctivitis 1, 3
- Bacterial resistance, particularly MRSA, is a growing concern with poor adherence to treatment regimens 1, 3