Differential Diagnosis for Red, Swollen Eyes
Single Most Likely Diagnosis
- Allergic Conjunctivitis: This is the most likely diagnosis given the symptoms of redness, swelling, itchiness, and minimal relief with Benadryl. The presence of drainage and dryness also supports this diagnosis, although the patient denies any allergies or new environmental exposures.
Other Likely Diagnoses
- Viral Conjunctivitis: The symptoms of redness, swelling, and drainage are consistent with viral conjunctivitis, which can be highly contagious. The lack of response to Benadryl and the presence of a headache and light sensitivity also support this diagnosis.
- Blepharitis: This condition involves inflammation of the eyelids and can cause redness, swelling, and itchiness. The patient's symptoms of dryness and itchiness in the eyebrow area could be related to blepharitis.
- Dry Eye Syndrome: The patient's complaint of dry eyes could be a primary condition or secondary to another condition such as blepharitis or conjunctivitis.
Do Not Miss Diagnoses
- Acute Angle-Closure Glaucoma: Although less likely, this condition is a medical emergency that requires prompt treatment. The patient's symptoms of light sensitivity, headache, and redness could be indicative of acute angle-closure glaucoma.
- Orbital Cellulitis: This is a serious infection that can cause redness, swelling, and pain around the eye. Although the patient's symptoms are bilateral, orbital cellulitis can occur in both eyes and requires prompt antibiotic treatment.
- Keratitis: This is an inflammation of the cornea that can cause redness, pain, and light sensitivity. If left untreated, keratitis can lead to serious complications, including vision loss.
Rare Diagnoses
- Sjögren's Syndrome: This is an autoimmune disorder that can cause dry eyes and other systemic symptoms. Although rare, Sjögren's syndrome could be considered if the patient's symptoms persist and other diagnoses are ruled out.
- Thyroid-Associated Orbitopathy: This condition can cause redness, swelling, and protrusion of the eyes. Although less likely, thyroid-associated orbitopathy could be considered if the patient has a history of thyroid disease or other systemic symptoms.