What causes conjunctival injection (bloodshot eyes)?

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Differential Diagnosis for Bloodshot Eyes

  • Single most likely diagnosis
    • Conjunctivitis: This is the most common cause of bloodshot eyes, often due to viral or bacterial infections, or allergic reactions. It's characterized by redness, itching, and discharge.
  • Other Likely diagnoses
    • Dry eye syndrome: Insufficient tear production or poor tear quality can lead to eye irritation and redness.
    • Eye strain: Prolonged use of computers, reading, or other visually demanding tasks can cause fatigue and redness in the eyes.
    • Allergies: Seasonal or environmental allergies can cause bloodshot eyes due to inflammation and irritation.
    • Contact lens-related issues: Poorly fitted lenses, lens hygiene issues, or sensitivity to lens cleaning solutions can lead to eye redness.
  • Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
    • Acute angle-closure glaucoma: A medical emergency characterized by sudden, severe eye pain, redness, and vision loss. If left untreated, it can lead to permanent vision loss.
    • Endophthalmitis: A rare but potentially devastating infection within the eye that requires prompt treatment to prevent vision loss.
    • Orbital cellulitis: A bacterial infection of the tissues surrounding the eye, which can lead to serious complications if not treated promptly.
  • Rare diagnoses
    • Sjögren's syndrome: An autoimmune disorder that can cause dry eyes and other systemic symptoms.
    • Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the eyes, leading to redness and vision problems.
    • Wegener's granulomatosis: A rare autoimmune disorder that can cause bloodshot eyes, among other symptoms, due to inflammation of blood vessels.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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