Introduction
Conjunctivitis, commonly known as “pink eye,” is inflammation of the conjunctiva — the thin, clear tissue that lines the inside of the eyelids and the outer surface of the eye. It may occur in one or both eyes. When both eyes are affected, viral causes are more likely. Patients typically present with discomfort, redness, and eye discharge. Conjunctivitis may be acute (resolving within 4 weeks) or chronic (lasting beyond 4 weeks). Most cases are self-limiting.
Epidemiology
- Very common; accounts for around 1% of physician visits.
- Viral infections cause about 80% of all cases.
- In children, bacterial conjunctivitis is more common (50–75%).
Classification & Etiology
1. Viral Conjunctivitis
The most common form (up to 80% of cases). Major causes include:
- Adenovirus (65–90% of viral cases)
- Herpes simplex virus (HSV)
- Molluscum contagiosum
- Varicella zoster
- Epstein–Barr virus
2. Bacterial Conjunctivitis
Common in children and older adults. Common pathogens include:
- Streptococcus pneumoniae
- Staphylococcus aureus
- Haemophilus influenzae
Specific Forms of Conjunctivitis
- Hyperacute conjunctivitis: Rapid, severe infection caused by Neisseria gonorrhoeae or N. meningitidis. Produces heavy purulent discharge and can be sight-threatening.
- HSV conjunctivitis: Usually unilateral; causes red eye with vesicular lesions on eyelids. HSV-1 common; HSV-2 mainly in neonates.
- Ophthalmia neonatorum: Conjunctivitis within first 28 days of life, commonly due to Chlamydia trachomatis, Neisseria gonorrhoeae, or other bacteria.
- Trachoma: Chronic keratoconjunctivitis caused by Chlamydia trachomatis; major cause of infectious blindness worldwide.
Clinical Features
- Bacterial: yellow/green discharge, redness, eyelid swelling, crusting of lashes.
- Viral: watery discharge, moderate redness, gritty or sandy sensation, light sensitivity.
- Allergic: watery discharge, itching (often severe), mild redness.
- Contact lens wearers may develop severe bacterial infections or corneal ulcers.
General Symptoms of Pink Eye
- Red eye
- Increased tearing
- Thick discharge (bacterial: yellow/green)
- Gritty sensation
- Itching or burning
- Blurred vision
- Light sensitivity
- Swollen eyelids
Diagnosis
Diagnosis is clinical and based on an eye examination.
- History taking (symptoms, onset, exposure).
- Visual acuity test.
- Examination of conjunctiva and external tissues under bright light.
- Evaluation of internal eye structures to rule out deeper infections.
- Cultures or smears in chronic or non-responsive cases.
Treatment Goals
- Relieve patient discomfort.
- Control the infection or inflammation.
- Prevent transmission in contagious cases.
General Management
- Warm compresses for bacterial discharge.
- Cold compresses for viral irritation.
- Artificial tears for dryness or burning.
- Frequent hand hygiene to prevent spread.
Treatment of Bacterial Conjunctivitis
Antibiotics are effective only for bacterial infections.
- Topical antibiotics (7–10 days): moxifloxacin, ciprofloxacin, trimethoprim/polymyxin.
- Ointments: preferred when tearing is excessive; may cause temporary blurring.
- Inclusion conjunctivitis: oral azithromycin, doxycycline, or erythromycin.
- Gonococcal conjunctivitis: single dose ceftriaxone injection + azithromycin (or doxycycline).
- Newborn prophylaxis: erythromycin ointment at birth.
Treatment of Viral Conjunctivitis
- Usually resolves in 1–2 weeks; no specific antiviral drops for most cases.
- Cool compresses and lubricants provide symptom relief.
- Topical corticosteroids only for severe adenoviral conjunctivitis (blurred vision, glare).
- Cyclosporine drops used rarely.
- EKC (Epidemic Keratoconjunctivitis) is highly contagious and requires strict hygiene.
Prevention
- Avoid touching/rubbing eyes.
- Use separate towels and washcloths.
- Frequent handwashing or sanitizer use.
- Avoid swimming pools during active infection.
- Stay home from school/work until major symptoms improve.
Detailed Notes:
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