Differential Diagnosis for Eye Redness with Pain
Single Most Likely Diagnosis
- Viral acute conjunctivitis: This is the most likely diagnosis given the symptoms of eye redness for 5 days with pain but no pus. Viral conjunctivitis is a common condition that presents with redness, irritation, and sometimes pain, but typically does not produce pus.
Other Likely Diagnoses
- Allergic conjunctivitis: This condition can cause eye redness and pain, especially if the patient has a history of allergies. It often presents with itching and tearing.
- Bacterial conjunctivitis (early stage): Although the question mentions no pus, early stages of bacterial conjunctivitis might not have significant discharge. It's a consideration, especially if the pain is severe.
- Dry eye syndrome: This condition can cause eye redness and pain due to insufficient lubrication of the eyes. It's more common in certain environments or with prolonged screen use.
Do Not Miss Diagnoses
- Acute angle-closure glaucoma: This is a medical emergency that can present with severe eye pain, redness, and blurred vision. It requires immediate treatment to prevent permanent vision loss.
- Corneal ulcer: An infection of the cornea can cause severe pain, redness, and sensitivity to light. It's a serious condition that needs prompt medical attention.
- Scleritis: Inflammation of the sclera can cause severe eye pain, redness, and tenderness to the touch. It's less common but can be associated with systemic diseases.
Rare Diagnoses
- Episcleritis: This is an inflammatory condition of the episclera, a thin layer on top of the sclera. It can cause eye redness and pain but is less common.
- Uveitis: Inflammation of the uvea, the middle layer of the eye, can cause eye pain, redness, and sensitivity to light. It's rare and often associated with systemic diseases or trauma.
- Keratitis: Inflammation of the cornea can be caused by infection, injury, or systemic disease, leading to eye redness and pain. Certain types, like herpes simplex keratitis, can be serious and recurrent.