Conjunctivitis: Viral

Conjunctivitis: Viral - The Eye Invaders

• Common Causative Viruses:
  • Adenovirus (most frequent)
  • Herpes Simplex Virus (HSV)
  • Varicella-Zoster Virus (VZV)
  • Enterovirus
  • Molluscum contagiosum virus
• Modes of Transmission:
  • Direct contact with infected ocular secretions.
  • Contaminated fomites (e.g., towels, makeup).
  • Respiratory droplets (especially for Adenovirus).
• Pathophysiology: Viruses replicate within conjunctival and corneal epithelial cells, leading to cell lysis and a subsequent inflammatory response.

⭐ Adenovirus is responsible for 65-90% of all viral conjunctivitis cases, making it the predominant etiological agent globally for this condition.

Conjunctivitis: Viral - Spotting Red Flags

• Key Symptoms:
  • Acute onset; typically unilateral, rapidly becoming bilateral.
  • Profuse watery discharge (serous).
  • Gritty/foreign body sensation, significant ocular redness (hyperemia), photophobia.
  • Itching usually mild (distinguishes from allergic).
• Critical Signs:

  • Diffuse conjunctival hyperemia; chemosis (swelling).

  • Follicular reaction: Small, elevated, translucent lesions, especially on inferior palpebral conjunctiva.

  • Tender preauricular lymphadenopathy: Hallmark sign. 📌 'A ViraL infection makes you PALe' (PreAuricular Lymphadenopathy).

  • Eyelid edema common. Severe cases (e.g., Epidemic Keratoconjunctivitis - EKC) may show petechial hemorrhages, pseudomembranes or true membranes.

⭐ The presence of tender preauricular lymphadenopathy is a strong indicator of viral conjunctivitis, particularly adenoviral.

Conjunctivitis: Viral - Identifying the Type

• Pharyngoconjunctival Fever (PCF): Triad: fever, pharyngitis, bilateral follicular conjunctivitis. Adenovirus types 3, 4, 7. Common in children, swimming pool outbreaks.

• Epidemic Keratoconjunctivitis (EKC): Highly contagious. Intense follicular conjunctivitis, pseudomembranes, characteristic subepithelial corneal infiltrates (SEIs) that can impair vision (vision ↓). Caused by Adenovirus types 8, 19, 37, 53, 54. Workplace/clinic outbreaks.

• Acute Hemorrhagic Conjunctivitis (AHC): Rapid onset, dramatic subconjunctival hemorrhages, chemosis, watery discharge. Caused by Enterovirus 70 and Coxsackievirus A24. Highly contagious, epidemic prone.

• Herpetic Conjunctivitis: Usually unilateral, associated with HSV keratitis (dendritic ulcer). Vesicular lesions on eyelids/margin. Follicular response. Reduced corneal sensation.

• Diagnosis: Primarily clinical. Rapid antigen detection tests for Adenovirus (e.g., AdenoPlus) can confirm. Viral culture/PCR for atypical/severe cases or herpetic suspicion.

⭐ Subepithelial infiltrates (SEIs) in Epidemic Keratoconjunctivitis (EKC) can persist for weeks to months, causing glare and decreased vision even after acute infection resolves.

Conjunctivitis: Viral - Damage Control Plan

• General (Most Types):
  • Supportive: PF artificial tears, cool compresses.
  • Hygiene: Handwash, no sharing.
• Adenoviral (PCF, EKC):
  • Self-limiting (1-3 weeks).
  • Povidone-Iodine 0.8-1.0% wash.
  • Severe (pseudomembranes, SEIs): Topical steroids (Loteprednol 0.5%), short course, taper. Rule out HSV.

  ⭐ The use of topical corticosteroids in adenoviral conjunctivitis is reserved for severe cases with pseudomembranes or symptomatic subepithelial infiltrates, and only after Herpes Simplex infection has been excluded.

• Herpetic Conjunctivitis:
  • Topical antivirals: Ganciclovir 0.15% gel 5x/d, Trifluridine 1% gtts 9x/d.
  • Oral acyclovir if extensive/recurrent.
  • ⚠️ Topical steroids contraindicated: active HSV epithelial keratitis.
• AHC: Supportive, self-resolves.
• Prevention: Educate re: contagion, isolate EKC/AHC, disinfect instruments.

High‑Yield Points - ⚡ Biggest Takeaways

• Adenovirus is the most common cause of viral conjunctivitis.
• Key signs: acute onset, watery discharge, follicles, tender preauricular lymphadenopathy (PAL).
• EKC (Adenovirus 8, 19, 37) causes severe keratitis with subepithelial infiltrates (SEIs).
• PCF (Adenovirus 3, 4, 7) presents with fever, pharyngitis, and follicular conjunctivitis.
• Treatment is mainly supportive; topical steroids used cautiously for severe non-herpetic keratitis.
• Highly contagious; strict hand hygiene is vital to prevent spread.