Differential Diagnosis for a 17-year-old with Red Eye, Irritation, and Watery Discharge
- Single most likely diagnosis:
- Viral conjunctivitis: This is the most likely diagnosis given the acute onset of red eye, irritation, and watery discharge, especially since the patient woke up with the symptoms. The use of castor oil in her lashes for months is less likely to cause such an acute presentation.
- Other Likely diagnoses:
- Allergic conjunctivitis: Although the patient has been using castor oil for months, it's possible that she recently developed an allergic reaction to it, or another allergen, leading to her symptoms.
- Bacterial conjunctivitis: This could be a consideration, especially if the discharge becomes more purulent, but the initial presentation of watery discharge and the lack of a reported injury or recent introduction of a new product make it less likely than viral conjunctivitis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed):
- Acute angle-closure glaucoma: Although rare in a 17-year-old, this condition can present with red eye, pain, and blurred vision, and is an emergency that requires immediate treatment.
- Keratitis (corneal ulcer): This can be caused by an infection or injury and can lead to serious complications, including vision loss, if not promptly treated.
- Scleritis or episcleritis: These are inflammatory conditions that can cause severe eye pain and redness and may be associated with systemic diseases.
- Rare diagnoses:
- Phlyctenular keratoconjunctivitis: An allergic type of conjunctivitis that can cause redness, irritation, and discharge, often associated with a history of atopy.
- Gonococcal conjunctivitis: A rare but serious condition that can cause severe conjunctivitis and is usually seen in neonates or young adults with a history of sexually transmitted infections.