Conjunctivitis and the Red Eye

Differential diagnosis of Conjunctivitis 1,2,3

Condition Pain Visual Acuity Photophobia Discharge Conjunctiva Lymphadenopathy Laterality Associated Features
Viral conjunctivitis None Unaffected None + watery ++ follicular pattern Pre-auricular Unilateral, spreads bilateral Viral URI
Bacterial conjunctivitis None Unaffected None ++ purulent +++ papillary pattern Occasional Unilateral, spreads bilateral Otitis media
Allergic conjunctivitis None Unaffected None + mucoid + None Bilateral Atopy

Differential Diagnosis of Red Eye 4,5

Condition Comment Hyperemia Pupil Pain Visual Acuity Cornea
Subconjuntival hemorrhage Subconjunctival Hemorrhage Associated with trauma, coagulopathy, hypertension. Unilateral, sharply circumscribed Unaffected None Unaffected Clear
Blepharitis Blepharitis Acute/chronic inflammation of eyelid. Diffuse Unaffected Foreign body sensation Unaffected Clear
Epislceritis Episcleritis Recurrent, self-limited episodes, possible autoimmune association. Engorged, radially-oriented vessels Unaffected Mild Unaffected Clear
Scleritis Scleritis Vascular or connective tissue disease. Focal or diffuse, pink sclera Unaffected Moderate Reduced Clear
Acute angle-closure glaucoma Acute Angle-Closure Glaucoma Mydriasis leading to decreased outflow of aqueous humor. Circumcorneal injection Semi-dilated Severe Reduced Hazy
Acute anterior uveitis Uveitis Inflammation of iris or ciliary body. Circumcorneal injection Constricted Moderate Reduced Hazy
Keratitis Keratitis Inflammation of corneal epithelium. Caused by infection, contact lenses, UV exposure. Multiple punctate erosions, stain with fluorescein Unaffected Moderate Reduced Hazy

Algorithm for the Evaluation of the Red Eye 6

Algorithm for the Evaluation of the Red Eye


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  6. Borooah, S., Wright, M., & Dhillon, B. (2011). Ophthalmology. JP Medical Limited.