Differential Diagnosis for Red Itchy Eyes with Discharge
Single Most Likely Diagnosis
- Allergic Conjunctivitis: This is the most likely diagnosis due to the presence of itchiness, which is a hallmark symptom of allergic reactions. Allergic conjunctivitis is common and often presents with redness, itchiness, and discharge, especially in individuals with a history of allergies.
Other Likely Diagnoses
- Viral Conjunctivitis: This condition is highly contagious and can cause redness, itchiness, and discharge. It's often accompanied by a watery discharge and can be associated with upper respiratory infections.
- Bacterial Conjunctivitis: Although it tends to produce a thicker, more purulent discharge than viral conjunctivitis, bacterial conjunctivitis can also cause red, itchy eyes. It's more common in contact lens wearers or after an eye injury.
- Blepharitis: This is an inflammation of the eyelids that can cause itchiness, redness, and discharge. It's often associated with meibomian gland dysfunction and can be chronic.
Do Not Miss Diagnoses
- Acute Angle-Closure Glaucoma: Although it typically presents with severe eye pain and vision loss, acute angle-closure glaucoma can also cause redness and discharge. It's an emergency that requires immediate treatment to prevent permanent vision loss.
- Keratitis: An infection of the cornea, keratitis can cause pain, redness, and discharge. It's particularly concerning in contact lens wearers and can lead to serious complications if not treated promptly.
- Endophthalmitis: A severe infection within the eye, endophthalmitis is a rare but potentially devastating condition that can follow eye surgery or trauma. It presents with severe pain, redness, and vision loss.
Rare Diagnoses
- Trachoma: A chronic infection of the eye caused by Chlamydia trachomatis, trachoma can lead to chronic conjunctivitis and is a leading cause of preventable blindness worldwide. It's rare in developed countries but should be considered in individuals from endemic areas.
- Giant Papillary Conjunctivitis: This condition is associated with the use of contact lenses and can cause chronic inflammation and discomfort. It's less common than other forms of conjunctivitis but should be considered in contact lens wearers with persistent symptoms.