II. Epidemiology
- Viral Conjunctivitis is most common Conjunctivitis cause (80% of cases)- Viral Conjunctivitis accounts for 55 to 80% of Conjunctivitis cases in adults
- Bacterial Conjunctivitis is more common in children (up to 71% of cases)
 
- Typically spread by contaminated hands
- Viral sources can survive on fomites for up to 72 hours
- Common cause of Swimming Pool Conjunctivitis (esp. Adenovirus)- Chlorine does not eliminate Adenovirus
 
III. Causes
- 
                          Adenovirus (most common)- Highly contagious (survives up to 28 days, 30% transmission rate)
- Transmitted via fomites (e.g. fingers, cosmetics) and swimming pools
 
- Epidemic Keratoconjunctivitis (more severe, Lymphadenopathy)
- Enterovirus
- Coxsackievirus
- Varicella Zoster Virus (Herpes Ophthalmicus)
- Epstein-Barr Virus (EBV, Mononucleosis)
- Herpes Simplex Virus (Herpes Keratitis)
- Influenza
IV. Symptoms
- Mild watery Eye Discharge or tearing
- Insidious onset over 36 hours
- Mild eye burning to no pain (eye may feel gritty)
- Mild eye itch
- Diffuse Conjunctival Hyperemia
- Unilateral initially and spreads to opposite eye within 1-2 days
- Associated symptoms- Upper Respiratory Infection
- Severe Pharyngitis with some infections (e.g. coxsackievirus, Mononucleosis)
 
V. Signs
- Marked Conjunctival erythema
- Epiphora (Eye tearing)
- 
                          Preauricular Lymphadenopathy (anterior to tragus)- Highly suggestive of Viral Conjunctivitis (especially Adenovirus)
 
- Mild palpebral Conjunctival follicular response
- Multiple small subepithelial Corneal infiltrates (severe cases)
- Fever
VI. Differential Diagnosis
VII. Precautions: Red Flags
- See Conjunctivitis
- See Herpes Ophthalmicus
VIII. Management
- Conditions requiring urgent ophthalmology referral
- Warm soaks to keep lids and lashes free of debris
- Cool compresses may be soothing
- Practice good hygiene to prevent contagious spread- Hosts shed Adenovirus for 10 to 14 days
- Avoid exposing others for at least 7 days, and at least until Red Eye and tearing resolves
 
- Topical lubricant eye drops (Methylcellulose, Refresh Tears) or artificial tears
- Remove Contact Lens and do not wear again until Conjunctivitis resolves
- Avoid Topical Corticosteroids (prolonged viral shedding, Glaucoma risk)
- 
                          Antibiotic not indicated in Viral Conjunctivitis- See Bacterial Conjunctivitis
- Risk of Antibiotic Resistance, transmission of Viral Conjunctivitis to contralateral eye, chemical Conjunctivitis
 
IX. Prevention
- Frequent Hand Washing
- Do not share towels, pillowcases or eye makeup
- Throw away used Contact Lenses and their case
- Throw away used eye makeup
- Avoid touching your face
- Wipe contaminated surfaces with bleach- Adenovirus survives on surfaces for 72 hours
 
X. Course
- Eye discomfort may persist for up to 10 days
- Infectious while excessive eye watering continues (typically 10-14 days)- Return if failed resolution by 2 to 3 weeks
 
XI. Resources (Include Patient Education)
XII. References
- Williams (2017) Crit Dec Emerg Med 31(2): 3-12
- Cronau (2010) Am Fam Physician 81(2): 137-44 [PubMed]
- Winters (2024) Am Fam Physician 110(2):134-44 [PubMed]
