Tests include blood work (CBC) to rule out infectious cause. Also perform a CT scan, x ray of the anterior skull to view the sinuses, MRI scan and finally a soft tissue ultrasound of the orbital region.
Periorbital cellulitis
Chalazion
Orbital cellulitis
Sympathetic ophthalmia
Blepharitis
Corneal ulcer
Periorbital dermatitis
Orbital lymphoma