Differential Diagnosis for Pink Eye

• Single most likely diagnosis
  • Viral conjunctivitis: This is the most common cause of pink eye, often presenting with redness, itching, and discharge in one or both eyes. It is highly contagious and usually resolves on its own.
• Other Likely diagnoses
  • Bacterial conjunctivitis: Caused by bacteria, this form of conjunctivitis can present with more pronounced discharge that is often thicker and more purulent than viral conjunctivitis. It may require antibiotic treatment.
  • Allergic conjunctivitis: This occurs in response to an allergen and is characterized by intense itching, redness, and tearing. It is not contagious and can be treated with antihistamines or other allergy medications.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Gonococcal conjunctivitis: A severe form of conjunctivitis caused by the bacterium Neisseria gonorrhoeae. It can lead to rapid vision loss if not promptly treated with appropriate antibiotics.
  • Herpes simplex keratitis: An infection of the cornea caused by the herpes simplex virus. It can lead to serious complications, including vision loss, if not properly managed with antiviral medications.
• Rare diagnoses
  • Chlamydial conjunctivitis: Caused by Chlamydia trachomatis, this form of conjunctivitis can be sexually transmitted or acquired through contact with contaminated secretions. It requires specific antibiotic treatment.
  • Fungal conjunctivitis: A rare but potentially serious infection that can occur, especially in immunocompromised individuals or after trauma to the eye. It requires antifungal treatment.