Differential Diagnosis for Pink Eye in a 6-Month-Old
Single Most Likely Diagnosis
- Viral Conjunctivitis: This is the most common cause of pink eye in infants, often caused by adenovirus or herpes simplex virus. The justification for this diagnosis is the high prevalence of viral conjunctivitis in this age group and the typical presentation of redness, discharge, and tearing.
Other Likely Diagnoses
- Bacterial Conjunctivitis: This is another common cause of pink eye in infants, often caused by Staphylococcus aureus, Haemophilus influenzae, or Streptococcus pneumoniae. The justification for this diagnosis is the presence of purulent discharge and the potential for bacterial conjunctivitis to cause more severe symptoms.
- Allergic Conjunctivitis: This can occur in infants, especially if there is a family history of allergies. The justification for this diagnosis is the presence of itching, redness, and tearing, particularly if the infant is exposed to allergens.
- Chemical Conjunctivitis: This can occur in infants, especially if they are exposed to irritants such as shampoo or soap. The justification for this diagnosis is the presence of redness and tearing after exposure to a potential irritant.
Do Not Miss Diagnoses
- Gonococcal Conjunctivitis: This is a rare but serious cause of pink eye in infants, often acquired during birth from an infected mother. The justification for this diagnosis is the potential for gonococcal conjunctivitis to cause severe symptoms, including corneal perforation and vision loss, if left untreated.
- Herpes Simplex Keratoconjunctivitis: This is a serious cause of pink eye in infants, which can lead to vision loss if left untreated. The justification for this diagnosis is the potential for herpes simplex to cause severe symptoms, including corneal ulcers and scarring.
- Chlamydial Conjunctivitis: This is a common cause of conjunctivitis in infants, often acquired during birth from an infected mother. The justification for this diagnosis is the potential for chlamydial conjunctivitis to cause severe symptoms, including pneumonia and other systemic infections, if left untreated.
Rare Diagnoses
- Keratoconjunctivitis Sicca: This is a rare cause of pink eye in infants, often associated with autoimmune disorders. The justification for this diagnosis is the presence of dryness, redness, and tearing, particularly if the infant has a family history of autoimmune disorders.
- Sjögren's Syndrome: This is a rare autoimmune disorder that can cause conjunctivitis in infants. The justification for this diagnosis is the presence of dryness, redness, and tearing, particularly if the infant has a family history of autoimmune disorders.
- Tuberculous Conjunctivitis: This is a rare cause of pink eye in infants, often associated with systemic tuberculosis. The justification for this diagnosis is the presence of chronic conjunctivitis, particularly if the infant has a family history of tuberculosis or has been exposed to someone with tuberculosis.