Blepharitis or Hordeolum (Stye): Given Karli's history of dry eyes and a blocked duct, a stye or blepharitis is a common and likely diagnosis. The sudden worsening of symptoms, including swelling, inflammation, and pain, is consistent with a stye or blepharitis.

Chalazion: A chalazion is a blocked oil gland in the eyelid that can cause swelling, inflammation, and pain, similar to Karli's symptoms. Her history of a blocked duct increases the likelihood of this diagnosis.
Conjunctivitis: Conjunctivitis, also known as pink eye, can cause eyelid swelling, inflammation, and pain, especially if it is a bacterial or viral infection.
Dacryocystitis: Given Karli's history of a blocked duct, dacryocystitis (inflammation of the tear sac) is a possible diagnosis, especially if the blockage has led to an infection.

Orbital Cellulitis: Although less likely, orbital cellulitis is a serious infection that can cause eyelid swelling, inflammation, and pain. It requires prompt treatment to prevent serious complications, such as vision loss or cavernous sinus thrombosis.
Endophthalmitis: This is a rare but serious infection within the eye that can cause severe pain, swelling, and vision loss. It is a medical emergency that requires immediate attention.

Angioedema: Angioedema is a rare condition that can cause sudden, severe swelling of the eyelids, face, and lips. It can be life-threatening if it affects the airway.
Eyelid Malignancy: Although extremely rare, eyelid malignancies such as basal cell carcinoma or squamous cell carcinoma can cause swelling, inflammation, and pain. A thorough examination and biopsy would be necessary to diagnose these conditions.