Differential Diagnosis for a 5-year-old with Crusty Eye, Right OS Erythema, and Pruritus with White Crusty Drainage

• Single most likely diagnosis:
  • Blepharitis: This condition is characterized by inflammation of the eyelids, often associated with erythema, pruritus, and crusty discharge. It's common in children and can be caused by poor eyelid hygiene, allergies, or infections.
• Other Likely diagnoses:
  • Conjunctivitis (Viral or Bacterial): This is an infection or inflammation of the conjunctiva, which can cause redness, itching, and discharge. Both viral and bacterial conjunctivitis are common in children and can present with similar symptoms.
  • Allergic Conjunctivitis: This condition occurs due to an allergic reaction, leading to itching, redness, and sometimes a stringy discharge. It's common in children, especially those with other allergies.
• Do Not Miss diagnoses:
  • Gonococcal Conjunctivitis: Although less common, this condition is a serious infection that can cause severe conjunctivitis and is a significant concern in neonates but can also occur in older children, especially if there's a suspicion of sexual abuse.
  • Herpes Simplex Keratoconjunctivitis: This viral infection can cause severe inflammation of the cornea and conjunctiva, leading to vision loss if not treated promptly.
• Rare diagnoses:
  • Kawasaki Disease: This is a rare condition that can cause conjunctivitis among other systemic symptoms like fever, rash, and lymphadenopathy. It's more known for its cardiac complications.
  • Phthiriasis Palpebrarum (Eyelash Lice): A rare infestation of the eyelashes by lice, which can cause itching, redness, and sometimes a gritty sensation in the eyes.