History of Present Illness (HPI)

The patient is an 18-year-old female who presents with left eye irritation, clear drainage, sensitivity to light, and a sensation that something is inside or poking her left eye. She wears contact lenses but removed the left contact lens last night when symptoms started. Her last tetanus injection was in 2018. She denies any foreign body entering her eye.

Differential Diagnosis

• Single Most Likely Diagnosis
  • Contact Lens-Related Irritation or Infection: Given the patient's history of wearing contact lenses and the onset of symptoms after removing the lens, this is a highly plausible cause. The sensation of something being in the eye and the presence of clear drainage could be indicative of an irritation or early infection related to contact lens use.
• Other Likely Diagnoses
  • Dry Eye Syndrome: This condition can cause irritation, sensitivity to light, and a foreign body sensation in the eye, especially if the patient has been wearing contact lenses for an extended period.
  • Allergic Conjunctivitis: Seasonal or perennial allergies could cause eye irritation, clear discharge, and sensitivity to light, fitting the patient's symptoms.
  • Viral Conjunctivitis: This is a common condition that can cause eye irritation, discharge (which may be clear), and sensitivity to light, often accompanied by a sensation of having something in the eye.
• Do Not Miss Diagnoses
  • Corneal Ulcer: Although less likely, a corneal ulcer (possibly due to a bacterial infection) is a serious condition that could present with similar symptoms, including severe pain, redness, and a foreign body sensation. It requires prompt treatment to prevent vision loss.
  • Acute Angle-Closure Glaucoma: This is a medical emergency that can cause severe eye pain, blurred vision, sensitivity to light, and a feeling of fullness in the eye. It's less likely given the description but must be considered due to its potential for severe consequences.
• Rare Diagnoses
  • Scleritis or Episcleritis: Inflammatory conditions of the sclera or episclera that can cause severe eye pain, redness, and sensitivity to light. These conditions are less common but should be considered in the differential diagnosis due to their potential for serious complications.
  • Foreign Body in the Eye: Despite the patient's denial, a small foreign body could potentially be lodged in the eye, causing irritation and a foreign body sensation. This would be more likely if the patient had been in an environment where such an incident could occur (e.g., working with power tools, being in a windy or dusty area).