Differential Diagnosis for Swollen Red Eyelid

• Single most likely diagnosis
  • Blepharitis: This is an inflammation of the eyelids that can cause redness, swelling, and itching. It's a common condition and often presents with these symptoms, making it a likely first consideration.
• Other Likely diagnoses
  • Conjunctivitis: Also known as pink eye, this condition can cause the eyelid to become red and swollen due to infection or allergies.
  • Hordeolum (Stye): A localized infection or inflammation of the eyelid margin involving hair follicles of the eyelashes or meibomian glands. It presents as a painful, red, swollen nodule on the eyelid.
  • Chalazion: A small bump on the eyelid due to a blocked oil gland. While often painless, it can become inflamed and cause swelling and redness.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Orbital Cellulitis: A serious infection of the tissues surrounding the eye, which can cause swelling, redness, and pain of the eyelid. It requires prompt medical attention to prevent serious complications.
  • Angioedema: A condition characterized by rapid swelling of the dermis, subcutaneous tissue, mucosa, and submucosal tissues. It can cause significant swelling of the eyelids and, if part of an allergic reaction, can be life-threatening.
• Rare diagnoses
  • Erythema Multiforme: A skin condition characterized by target lesions, which can sometimes affect the eyelids, causing swelling and redness.
  • Malignant Tumors: Though rare, certain types of skin cancers or other malignancies can present with swelling and redness of the eyelid, emphasizing the importance of thorough examination and follow-up.