Differential Diagnosis for Headache with Conjunctivitis
- Single Most Likely Diagnosis
- Viral conjunctivitis: This is the most common cause of conjunctivitis and can be associated with headaches due to the viral infection itself or due to the discomfort and irritation caused by the conjunctivitis.
- Other Likely Diagnoses
- Sinusitis: Sinus infections can cause headaches and, if the infection spreads to the eyes, can also cause conjunctivitis.
- Allergic conjunctivitis: Seasonal allergies or other allergic reactions can cause conjunctivitis and may be associated with headaches due to the allergic response or sinus pressure.
- Migraine with conjunctival injection: Some migraines can cause conjunctival injection (redness of the conjunctiva) that may be mistaken for conjunctivitis, and are often accompanied by headaches.
- Do Not Miss Diagnoses
- Acute angle-closure glaucoma: Although less common, this condition can cause severe headaches and conjunctivitis. It is an ophthalmological emergency that requires immediate treatment to prevent vision loss.
- Meningitis: In rare cases, meningitis can present with conjunctivitis and severe headache. Given its high mortality rate if untreated, it is crucial not to miss this diagnosis.
- Encephalitis: Similar to meningitis, encephalitis is an infection of the brain that can cause a range of symptoms including headache and, less commonly, conjunctivitis. Its potential severity warrants consideration.
- Rare Diagnoses
- Sjögren's syndrome: An autoimmune disorder that can cause conjunctivitis and may be associated with headaches due to its systemic effects or associated conditions like fibromyalgia.
- Behçet's disease: A rare condition that can cause conjunctivitis among other symptoms, including headaches, due to its inflammatory nature affecting various parts of the body.
- Lyme disease: In some cases, Lyme disease can cause conjunctivitis and headaches, especially in the early stages of the disease.