Conjunctivitis

Disease Description (Causes and Symptoms)

• Definition: Conjunctivitis is inflammation of the conjunctiva, the membrane covering the surface of the eye and the inner surface of the eyelid. Its clinical presentation and treatment vary depending on the cause.
• Main causes: Viruses (mainly adenovirus), bacteria (micrococci, streptococci, staphylococci, Pseudomonas aeruginosa, etc.), Chlamydia, gonococci, herpes simplex virus, allergies (seasonal or perennial), chemicals and irritants (smoke, ultraviolet rays), contact lens-related infections, etc.
• Pathophysiology summary: Vasodilation, exudation, and cellular inflammation of the conjunctiva cause redness, discharge, and a foreign-body sensation. Some pathogens can invade the cornea and cause keratitis or ulcers, which may affect vision.
• Main symptoms: Redness, eye discharge (yellow or green purulent discharge suggests bacterial infection, while clear watery discharge suggests viral or allergic conjunctivitis), itching (especially prominent in allergic conjunctivitis), irritation or foreign-body sensation, tearing, photophobia (in severe cases), conjunctival swelling (papillae or follicles), and, rarely, decreased vision (when the cornea is involved).

Treatment (Standard Treatment · Medication · Lifestyle Management · Precautions)

• General principles:
  • Treatment is determined according to severity and cause. If corneal involvement is suspected (pain, decreased vision, extensive redness, or fluorescein-positive lesions), immediate ophthalmologic evaluation is necessary.
  • Culture and antibiotic susceptibility testing are recommended when the cause is unknown, the condition is severe, or symptoms are worsening.
• Bacterial conjunctivitis:
  • Mild outpatient cases: Broad-spectrum ophthalmic antibiotics (e.g., quinolones such as moxifloxacin or levofloxacin, or aminoglycoside/cephalosporin preparations) 3–4 times daily, usually for 5–7 days.
  • If neonatal conjunctivitis or infection with a special pathogen (such as gonococci) is suspected, consider systemic treatment and hospitalization (gonococcal infection: immediate intravenous/intramuscular ceftriaxone/ceftriaxone or treatment according to the latest guidelines).
• Viral conjunctivitis:
  • Most cases are treated symptomatically (cold compresses, artificial tears, and hygiene). When antiviral medication may be needed (such as herpes simplex), it must be prescribed by a specialist.
  • There is no specific antiviral medication for adenoviral conjunctivitis; it may remain contagious for a prolonged period.
• Chlamydial conjunctivitis:
  • Adults: A single oral dose of azithromycin 1 g or doxycycline 100 mg twice daily for 7 days.
  • Neonates: Systemic antibiotics (e.g., oral erythromycin) are required.
• Herpes simplex conjunctivitis:
  • Treatment with a topical antiviral (such as trifluridine) or acyclovir (topical/systemic); ophthalmologist instructions are essential.
• Gonococcal conjunctivitis:
  • An emergency; systemic antibiotics (e.g., ceftriaxone), topical treatment, and hospitalization should be considered.
• Allergic conjunctivitis:
  • Cold compresses, artificial tears, topical antihistamines, or antihistamine/mast-cell stabilizer eye drops; in severe cases, short-term topical corticosteroids may be used at the discretion of a specialist.
• Contact lens-related:
  • Stop wearing lenses immediately, discard and disinfect the lens case, and seek emergency ophthalmologic care immediately if corneal involvement is suspected (due to the risk of serious pathogens such as Pseudomonas aeruginosa).
• Lifestyle management and infection prevention:
  • Practice thorough hand hygiene, do not share towels, cosmetics, or pillows, avoid touching the eyes, and wipe away discharge with clean gauze.
• Major precautions:
  • Do not use topical corticosteroids when corneal infection (ulcer) has not been ruled out; use them only under professional guidance.
  • Neonates and contact lens users have a higher risk of complications and should be evaluated promptly.

Checklist Before an Outpatient Visit (Recommended Items to Bring and Example Questions)

• Recommended items to bring:
  • A list of current medications (including eye drops), allergy history, recent ophthalmology prescriptions or test results (if available), contact lenses and their case, notes on when the condition began and how symptoms have changed, and, for a neonate, the mother’s health status and delivery history.
• Key information to provide to the doctor:
  • Date symptoms began, whether one or both eyes are affected, the nature of the discharge (clear/sticky/purulent), whether there is pain (severe pain suggests possible corneal involvement), whether there is decreased vision or photophobia, recent upper respiratory infection or an outbreak in a group setting (kindergarten or school), history of sexual intercourse (risk of gonococcal infection or Chlamydia), and whether there is immunosuppression.
• Possible tests: Eye examination (slit-lamp examination), fluorescein staining (to check for corneal damage), culture (if necessary), and, for neonates, evaluation for systemic infection.

General Example Questions to Ask the Doctor

• What effects can be expected from this medication (eye drops/oral medication), and what side effects are possible?
• How many days does it usually take for symptoms to improve after starting treatment? When should I return for another visit?
• Is this condition contagious to other people? When can I return to daycare/school/work?
• Is there a possibility of permanent damage to the eye or vision?

Examples of Condition-Specific Questions

• Contact lens-related: "When can I start wearing contact lenses again? How should I handle the lenses and their case?"
• Neonate/mother-related: "What tests are needed to determine the cause of neonatal conjunctivitis, and does the mother also need treatment? What symptoms require hospitalization or systemic treatment?"