Epidemiology & Risk Factors
- Highly contagious; spread via direct contact/fomites.
- Most common pathogens (Adults): S. aureus. c
- Most common pathogens (Kids): S. pneumoniae, H. influenzae, M. catarrhalis.
- Contact lens wearers: Pseudomonas aeruginosa is highly prevalent and dangerous.
- Neonates: Vertical transmission of N. gonorrhoeae or C. trachomatis.
Clinical Features
- Thick, purulent discharge (yellow, green, or white) that continues throughout the day.
- Eyelids “stuck shut” in the morning (crusting/matting).
- Unilateral onset, but often spreads to the contralateral eye.
- Conjunctival injection/erythema and chemosis.
- Minimal to no itching (diff from allergic).
- No changes in visual acuity, pupillary reflex, or corneal clarity.
Diagnosis
- Initial: Clinical diagnosis based on history and physical exam (empiric Tx started immediately).
- Key Labs: Conjunctival swab for Gram stain, culture, and PCR.
- Indicated only for: contact lens wearers, neonates, suspected hyperacute gonococcal infection, or cases refractory to standard empiric Abx.
- Slit-lamp exam: Assesses for corneal involvement (fluorescein staining to rule out keratitis/corneal ulcer).
Differential Diagnostics
- Viral Conjunctivitis: Diff by watery/mucoid discharge, prominent preauricular lymphadenopathy, and viral prodrome (pharyngitis, fever).
- Allergic Conjunctivitis: Diff by bilateral intense pruritus (itching), watery discharge, and history of atopy.
- Chlamydial Conjunctivitis (Adult Inclusion Conjunctivitis): Diff by chronic course (>2–3 weeks) refractory to standard topical Abx, follicular tarsal conjunctivitis (cobblestone appearance of palpebral conjunctiva), nontender preauricular LN, and concurrent urogenital symptoms (urethritis/cervicitis).
- Keratitis: Diff by severe eye pain, photophobia, decreased visual acuity, and corneal opacity/ulcer on fluorescein stain.
- Neonatal Conjunctivitis: Diff by timing of onset:
- Chemical: < 24 hours post-birth (due to silver nitrate prophylaxis).
- Gonococcal: 2–5 days post-birth (marked eyelid swelling, profuse purulent discharge, risk of blindness).
- Chlamydial: 5–14 days post-birth (mild to moderate purulent discharge, associated with pneumonia).
Management
- Non-contact lens wearers: Erythromycin ophthalmic ointment OR Polymyxin B/Trimethoprim drops for 5–7 days.
- Contact lens wearers: Topical fluoroquinolones (e.g., Moxifloxacin, Ofloxacin) to cover Pseudomonas. Discontinue lens wear until fully resolved.
- Gonococcal Conjunctivitis: Urgent single dose of systemic Ceftriaxone (IM/IV) + topical saline irrigation.
- Chlamydial Conjunctivitis: Oral Azithromycin or Doxycycline (systemic Tx required; topical is insufficient). Neonates require oral Erythromycin (monitor for pyloric stenosis).
Complications
- Keratitis or corneal ulceration.
- Corneal perforation and permanent vision loss (especially with N. gonorrhoeae or Pseudomonas).
- Dacryocystitis or preseptal cellulitis.