View source for Bilateral red eyes

==Background==
[[File:Schematic diagram of the human eye en.png|thumb|Eye anatomy.]]
*This page describes a general approach to the complaint of bilateral red eyes<ref>Cronau H, Kankanala RR, Mauger T. Diagnosis and management of red eye in primary care. Am Fam Physician. 2010 Jan 15;81(2):137-44. PMID 20082509</ref>
*Bilateral red eye is more suggestive of a systemic or non-infectious process compared to unilateral red eye
*Most common cause is bilateral viral [[conjunctivitis]] (often starts unilateral, becomes bilateral in 24-48 hours)
*Key EM considerations: differentiate benign conjunctivitis from sight-threatening or systemic causes
*Bilateral conjunctival injection without exudate is a criterion for [[Kawasaki disease]] in children

==Clinical Features==
===History===
*Onset and progression (simultaneous vs. sequential)
*Type of discharge: watery (viral, allergic), purulent (bacterial), mucoid (allergic)
*Itching (suggests allergic etiology)
*Pain, photophobia (suggests deeper inflammation — scleritis, uveitis, keratitis)
*Vision changes (requires urgent evaluation)
*Contact lens use (bilateral keratitis)
*Recent URI (adenoviral conjunctivitis)
*Medication use (topical agents can cause bilateral toxic/allergic reaction)
*Systemic symptoms: joint pain (reactive arthritis), rash, fever (systemic disease)
*Seasonal pattern (allergic conjunctivitis)
*Chemical or irritant exposure
*Dry eye symptoms

===Physical Exam===
*Visual acuity (each eye separately) — must be normal in simple conjunctivitis<ref>Leibowitz HM. The red eye. N Engl J Med. 2000 Aug 3;343(5):345-51. PMID 10922425</ref>
*Type of injection: diffuse (conjunctivitis), ciliary flush (iritis, acute glaucoma)
*Pupil size and reactivity (irregular/fixed pupil = iritis or glaucoma)
*Discharge character
*Lid/periorbital edema
*Preauricular lymphadenopathy (viral conjunctivitis)
*Fluorescein staining (dendritic lesions = herpes, corneal abrasions)
*Evaluate for systemic findings: joint swelling (reactive arthritis), oral ulcers, rash

===Red Flags===
*Decreased visual acuity
*Photophobia + pain (not just irritation)
*Fixed or irregular pupils
*Ciliary flush (limbal injection)
*Contact lens wearer with pain and redness → corneal ulcer until proven otherwise
*Bilateral non-exudative conjunctival injection + fever in child → consider [[Kawasaki disease]]

==Differential Diagnosis==
{{Bilateral Red Eyes}}

===Common===
*Viral conjunctivitis (adenovirus — most common; highly contagious)
*Allergic conjunctivitis (bilateral itching, watery discharge, seasonal)
*Dry eye syndrome
*Chemical/irritant exposure

===Systemic Disease-Associated===
*Reactive arthritis (Reiter syndrome — conjunctivitis + urethritis + arthritis)
*[[Kawasaki disease]] (bilateral non-exudative, pediatric)
*[[Stevens-Johnson syndrome]] / toxic epidermal necrolysis (bilateral conjunctivitis with skin involvement)
*[[SLE]] (episcleritis/scleritis)
*Inflammatory bowel disease (episcleritis, uveitis)
*Thyroid eye disease (Graves' — may have bilateral injection with proptosis)

===Infectious===
*'''Gonococcal conjunctivitis''' (hyperacute, profuse purulent discharge — emergency)
*Chlamydial conjunctivitis (chronic follicular conjunctivitis)
*Bilateral herpes keratitis (rare — consider immunocompromised)

==Evaluation==
===Bedside===
*Visual acuity (each eye)
*Fluorescein exam with slit lamp or Wood's lamp
*Pupillary exam
*IOP if glaucoma suspected

===Laboratory===
*Not needed for typical viral or allergic conjunctivitis
*Conjunctival swab for culture/Gram stain if: hyperacute purulent discharge, neonatal, not responding to treatment, concern for gonococcal
*Consider CBC, ESR/CRP if systemic disease suspected
*STI testing if reactive arthritis or gonococcal conjunctivitis suspected

==Management==
===Viral Conjunctivitis===
*Supportive care: cool compresses, artificial tears
*Strict hygiene education (highly contagious for 10-14 days)
*No topical antibiotics needed

===Allergic Conjunctivitis===
*Cool compresses
*Topical antihistamine/mast cell stabilizer drops (olopatadine, ketotifen)
*Oral antihistamines for systemic symptoms
*Avoid known allergens

===Bacterial Conjunctivitis===
*Topical antibiotic drops (polymyxin B-trimethoprim, erythromycin ointment)
*Gonococcal: systemic [[ceftriaxone]] + frequent saline irrigation + ophthalmology consultation

===Systemic Disease===
*Kawasaki disease: see [[Kawasaki disease]] protocol (IVIG + aspirin)
*Stevens-Johnson: admit, ophthalmology consultation, stop offending drug
*Reactive arthritis: NSAIDs, STI treatment if indicated

==Disposition==
===Discharge (Most Patients)===
*Viral conjunctivitis with reassurance and hygiene education
*Allergic conjunctivitis with treatment
*Return precautions: vision changes, worsening pain, photophobia, not improving in 7-10 days

===Emergent Ophthalmology===
*Gonococcal conjunctivitis
*Stevens-Johnson syndrome with ocular involvement
*Suspected bilateral keratitis

==See Also==
{{Eye algorithms}}
*[[Unilateral red eye]]
*[[Red eye (peds)]]
*[[Conjunctivitis]]
*[[Kawasaki disease]]

==References==
<references/>

[[Category:Ophthalmology]]
[[Category:Symptoms]]