Overview of conjunctivitis

Last updated: May 15, 2023

Summarytoggle arrow icon

Conjunctivitis is an inflammation of the conjunctiva that is sometimes accompanied by corneal inflammation (keratoconjunctivitis). The etiology of conjunctivitis can be infectious or noninfectious (e.g., allergic conjunctivitis). Common clinical findings include itching, burning, and ocular discharge; the clinical presentation sometimes suggests the underlying etiology (e.g., infections may manifest with purulent discharge, while keratoconjunctivitis sicca is characterized by dry eye). Conjunctivitis is the most common cause of ocular hyperemia but differential diagnoses include keratitis, acute glaucoma, and subconjunctival hemorrhages. Treatment depends upon the underlying cause; viral conjunctivitis is usually self-limited and requires only supportive therapy for conjunctivitis, whereas most types of bacterial conjunctivitis require antibiotics. Treatment of noninfectious conjunctivitis may include behavior changes (e.g., reducing contact lens use), topical treatment, or systemic treatments. If symptoms are severe or recurrent, or complex etiologies are suspected (e.g., autoimmune conditions), patients should be referred to an ophthalmologist early for specialized management. Surgical intervention is rarely necessary.

For more comprehensive information on the diagnosis and management of conjunctivitis subtypes, see “Bacterial conjunctivitis,” “Viral conjunctivitis,” and “Noninfectious conjunctivitis.” For management in newborns, see “Neonatal conjunctivitis.”

Conjunctivitis subtypestoggle arrow icon

Overview of conjunctivitis subtypes in children and adults [1][2][3]

Viral conjunctivitis

Bacterial conjunctivitis

Allergic conjunctivitis [1][4]

Acute bacterial conjunctivitis Gonococcal conjunctivitis [5] Trachoma
Clinical features
  • Unilateral or bilateral [2]
  • Clear, watery discharge (with mucoid component)
  • Increased lacrimation (epiphora)
  • Extraocular signs of viral infections (e.g., upper respiratory symptoms, preauricular lymphadenopathy)
  • Typically unilateral but may be bilateral
  • Thick mucopurulent discharge
  • Difficulty opening eyes in the morning

Clinical featurestoggle arrow icon

Conjunctivitis is the most common cause of red eye and is usually a clinical diagnosis. [2]

Red flags in conjunctivitistoggle arrow icon

Red flags in conjunctivitis indicate severe etiologies that require specialized management.

Diagnosticstoggle arrow icon

Conjunctivitis is usually a clinical diagnosis. Consider diagnostic studies if there is diagnostic uncertainty or suspicion for a serious infection. [1][2][3]

Treatmenttoggle arrow icon

General principles

Conjunctivitis is usually a self-limited condition and complications (e.g., vision loss, permanent eye damage) are rare. Most patients only require supportive therapy. [1]

Patient education is vital to prevent conjunctivitis outbreaks.

Supportive therapy for conjunctivitis [1][2][3]

  • Apply refrigerated artificial tears as often as needed.
  • Eyelid hygiene e.g.,
    • Saline irrigation
    • Remove eyelid discharge frequently
    • Avoiding touching the affected eye
    • Wash hands before and after cleaning the eye/applying eye drops
  • Compresses (can be warm or cold)
  • Advise patients to stop using contact lenses for ≥ 2 weeks. [6]
  • Educate patients on the prevention of conjunctivitis.

Differential diagnosestoggle arrow icon

The differential diagnoses listed here are not exhaustive.

Preventiontoggle arrow icon

Prevention of infectious conjunctivitis [1]

  • Educate patients on general preventive measures.
  • To prevent onward transmission, advise patients with active infections to:
    • Isolate at home if possible. [1]
    • Disinfect hands and surfaces frequently.
    • Avoid sharing items (e.g., towels, cosmetics).
    • Remove contact lenses, discard disposable lenses, and avoid wearing lenses again for ≥ 2 weeks. [6]

Prevention of noninfectious conjunctivitis [1]

Referencestoggle arrow icon

  1. Varu DM, Rhee MK, Akpek EK, et al. Conjunctivitis Preferred Practice Pattern®. Ophthalmology. 2019; 126 (1): p.P94-P169.doi: 10.1016/j.ophtha.2018.10.020 . | Open in Read by QxMD
  2. Azari AA, Barney NP. Conjunctivitis. JAMA. 2013; 310 (16): p.1721.doi: 10.1001/jama.2013.280318 . | Open in Read by QxMD
  3. Bielory L, et al. ICON: Diagnosis and management of allergic conjunctivitis. Ann Allergy Asthma Immunol. 2020; 124 (2): p.118-134.doi: 10.1016/j.anai.2019.11.014 . | Open in Read by QxMD
  4. Cronau H, Kankanala RR, Mauger T. Diagnosis and management of red eye in primary care. Am Fam Physician. 2010; 81 (2): p.137-44.
  5. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR. Recommendations and Reports. 2021; 70 (4): p.1-187.doi: 10.15585/mmwr.rr7004a1 . | Open in Read by QxMD
  6. Cope JR, Collier SA, Nethercut H, Jones JM, Yates K, Yoder JS. Risk Behaviors for Contact Lens–Related Eye Infections Among Adults and Adolescents — United States, 2016. MMWR Morb Mortal Wkly Rep. 2017; 66 (32): p.841-845.doi: 10.15585/mmwr.mm6632a2 . | Open in Read by QxMD
  7. Walls R, Hockberger R, Gausche-Hill M, Erickson TB, Wilcox SR. Rosen's Emergency Medicine 10th edition- Concepts and Clinical Practice E-Book. Elsevier Health Sciences ; 2022

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