Differential Diagnosis for Tear in One Eye of a 2-Month-Old Boy
Single Most Likely Diagnosis
- Nasolacrimal Duct Obstruction (NLDO): This condition is the most common cause of excessive tearing in infants. It occurs when the nasolacrimal duct, which drains tears from the eye into the nasal cavity, is blocked. This is often due to a membrane at the end of the duct that fails to open at birth. It typically presents unilaterally and is noticed in the first few weeks of life.
Other Likely Diagnoses
- Conjunctivitis: This is an inflammation or infection of the outer membrane of the eyeball and the inner eyelid. It can cause tearing, redness, and discharge. In a 2-month-old, it could be viral, bacterial, or allergic in nature.
- Foreign Body: A small object in the eye can cause irritation, leading to tearing. This is less common in infants due to their limited mobility and interaction with their environment but is still a possibility.
- Corneal Abrasion: Although less common in infants, a scratch on the cornea can cause significant discomfort, tearing, and sensitivity to light.
Do Not Miss Diagnoses
- Glaucoma: Congenital glaucoma is a rare condition that can cause tearing, photophobia, and eye enlargement. It is crucial to diagnose and treat early to prevent vision loss.
- Orbital Cellulitis: An infection of the tissues surrounding the eye, which can cause tearing, redness, swelling, and proptosis (bulging of the eye). This condition requires prompt antibiotic treatment to prevent serious complications.
- Retinoblastoma: Although extremely rare and typically presenting with other symptoms like leukocoria (white reflex), it's a critical diagnosis not to miss due to its severe implications.
Rare Diagnoses
- Lacrimal Sac Mucocele or Dacryocystocele: A condition where the lacrimal sac is filled with mucous or fluid, potentially causing tearing and swelling in the area of the lacrimal sac.
- Canaliculitis: An infection of the canaliculi (small ducts that collect tears from the eye), which can cause tearing, redness, and discharge.
- Congenital Anomalies of the Lacrimal System: Other than NLDO, there are various congenital anomalies that can affect the lacrimal system, leading to tearing. These are rare and often diagnosed after other common causes have been ruled out.