Differential Diagnosis for Sudden Onset Eye Swelling

The patient presents with sudden onset eye swelling, tearing, and discomfort without a history of trauma or foreign body exposure. The key findings include mild periorbital swelling, intact extraocular movements (EOMs), and normal visual acuity, with the eye showing clear discharge and mild yellowing.

• Single Most Likely Diagnosis

  • Allergic Conjunctivitis: This is the most likely diagnosis given the sudden onset of symptoms, including tearing, discomfort, and mild periorbital swelling, without any history of trauma. The presence of clear discharge further supports this diagnosis, as allergic reactions often lead to increased tearing and a watery discharge.

• Other Likely Diagnoses

  • Viral Conjunctivitis: This condition could present similarly to allergic conjunctivitis, with symptoms including eye redness, tearing, and discharge. However, viral conjunctivitis might have a more pronounced yellow or greenish discharge.
  • Blepharitis: Inflammation of the eyelids can cause swelling, redness, and discomfort, along with discharge. It's a common condition that could fit the patient's symptoms, especially if the discharge is described as mild and yellowish.
  • Dry Eye Syndrome: Although less likely given the acute onset, dry eye could cause discomfort and tearing, especially if the environment is dry or if the patient has been sitting in front of a screen for an extended period.

• Do Not Miss Diagnoses

  • Acute Angle-Closure Glaucoma: Although the patient's visual acuity is intact, and there's no mention of severe pain or blurred vision, acute angle-closure glaucoma is an emergency that must be considered. It can present with eye redness, tearing, and discomfort, along with elevated intraocular pressure.
  • Orbital Cellulitis: This is an infection of the tissues surrounding the eye, which can cause swelling, redness, and pain. It's a serious condition that requires prompt antibiotic treatment.
  • Keratitis: Inflammation of the cornea can cause pain, redness, and tearing. It's essential to examine the cornea closely for any signs of keratitis, especially if the patient has a history of contact lens use.

• Rare Diagnoses

  • Thyroid Ophthalmopathy: This condition, associated with Graves' disease, can cause eye swelling and discomfort due to inflammation of the tissues around the eye. However, it typically has a more gradual onset and is associated with other systemic symptoms.
  • Sjögren's Syndrome: An autoimmune disorder that can cause dry eyes and mouth. While it's less likely given the acute presentation, it could be considered in the differential diagnosis, especially if the patient has other systemic symptoms suggestive of an autoimmune disorder.

Treatment Approach

The treatment will depend on the final diagnosis. For allergic conjunctivitis, antihistamines and mast cell stabilizers can be effective. Viral conjunctivitis is typically self-limiting, but supportive care with artificial tears can help. Blepharitis may require eyelid hygiene and possibly antibiotics. Dry eye syndrome is managed with artificial tears and lifestyle modifications. For the "do not miss" diagnoses, immediate referral to an ophthalmologist or emergency department is crucial for conditions like acute angle-closure glaucoma and orbital cellulitis.