Differential Diagnosis for 6 Month Old with Unilateral Conjunctivitis
- Single Most Likely Diagnosis
- Nasolacrimal duct obstruction (NLDO): This is a common condition in infants, where the tear duct is blocked, leading to conjunctivitis. The presentation of unilateral conjunctivitis in a 6-month-old infant is highly suggestive of NLDO.
- Other Likely Diagnoses
- Viral conjunctivitis: Although less common in infants, viral conjunctivitis can still occur and may present unilaterally.
- Bacterial conjunctivitis: This can be caused by various bacteria, including Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae.
- Allergic conjunctivitis: Although less common in infants, allergic conjunctivitis can occur and may present unilaterally.
- Do Not Miss Diagnoses
- Gonococcal conjunctivitis: This is a serious condition that can cause severe conjunctivitis and potentially lead to vision loss if left untreated. It is essential to consider this diagnosis, especially if the infant has been exposed to Neisseria gonorrhoeae.
- Chlamydial conjunctivitis: Similar to gonococcal conjunctivitis, chlamydial conjunctivitis is a serious condition that requires prompt treatment to prevent long-term complications.
- Herpes simplex virus (HSV) conjunctivitis: HSV can cause severe conjunctivitis and potentially lead to vision loss or other complications if left untreated.
- Rare Diagnoses
- Congenital glaucoma: Although rare, congenital glaucoma can present with conjunctivitis and eye irritation.
- Sjögren's syndrome: This is an autoimmune disorder that can cause conjunctivitis, but it is extremely rare in infants.
- Foreign body: A foreign body in the eye can cause conjunctivitis, but this is less common in infants who are less likely to have objects in their eyes.