Differential Diagnosis for Posterior Lid Violaceous and Painful

• Single most likely diagnosis
  • Periorbital or Orbital Cellulitis: This condition is characterized by an infection of the tissues surrounding the eye, which can cause pain, swelling, and discoloration, including a violaceous hue due to the infection and potential hemorrhage.
• Other Likely diagnoses
  • Chalazion: Although typically not violaceous, a large or infected chalazion could cause significant pain and swelling, potentially leading to a change in lid color.
  • Hordeolum (Stye): An internal hordeolum could cause pain and swelling on the inside of the eyelid, potentially leading to a violaceous appearance if it becomes large or infected.
  • Blepharitis: In severe cases, especially if associated with a significant inflammatory response or infection, blepharitis could lead to pain and changes in eyelid appearance.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Cavernous Sinus Thrombosis: A rare but potentially life-threatening condition that can arise from facial or orbital infections, characterized by thrombosis of the cavernous sinus, which could present with pain, swelling, and color changes around the eye.
  • Orbital Abscess: A collection of pus in the orbit that can cause severe pain, proptosis, and vision changes, and if not promptly treated, can lead to serious complications including vision loss and intracranial infection.
• Rare diagnoses
  • Angioedema: A condition characterized by rapid swelling of the dermis, subcutaneous tissue, mucosa, and submucosal tissues, which can cause significant pain and swelling, including a violaceous appearance due to the extent of the swelling.
  • Granuloma Faciale: A rare skin condition that can cause purple lesions on the face, including around the eyes, though it's less likely to cause significant pain compared to other conditions listed.