Blepharitis: This condition is characterized by inflammation of the eyelids, which can cause redness, swelling, and warmth. The presence of chemosis (swelling of the conjunctiva) and clear drainage supports this diagnosis, as blepharitis often involves the conjunctiva and can lead to excessive tearing or discharge.

Conjunctivitis: This is an inflammation or infection of the outer membrane of the eyeball and the inner eyelid. It can cause redness, itching, and discharge, which aligns with the symptoms described. The clear drainage mentioned could be a sign of viral or allergic conjunctivitis.
Hordeolum (Stye): A stye is an infection of an oil gland or hair follicle on the eyelid. It can cause localized redness, swelling, and warmth, similar to what is described. However, a stye typically presents as a painful, localized nodule, which is not explicitly mentioned.
Dacryocystitis: This condition involves inflammation of the lacrimal sac, usually due to a blockage of the nasolacrimal duct. It can cause swelling, redness, and discharge, particularly in the medial canthus area. The clear drainage and swelling could be indicative of this condition, especially if there's an issue with tear drainage.

Orbital Cellulitis: Although the patient is afebrile and there are no vision changes, orbital cellulitis is a serious infection of the tissues surrounding the eye that requires prompt treatment. It can present with eyelid swelling, redness, and warmth, and it's crucial not to miss this diagnosis due to its potential for serious complications, including vision loss.
Angioedema: This condition involves rapid swelling of the dermis, subcutaneous tissue, mucosa, and submucosal tissues. It can cause significant eyelid swelling and, if part of an allergic reaction, could be life-threatening if not recognized and treated promptly.

Granuloma Faciale: A rare, chronic inflammatory condition that can cause single or multiple nodules on the face, including the eyelids. It might present with localized redness and swelling but is less likely given the acute presentation described.
Sarcoidosis: A systemic disease that can affect any organ, including the eyes. Ocular manifestations can include uveitis, conjunctivitis, and eyelid swelling. While it's a rare condition, its potential for multi-system involvement makes it worth considering in a differential diagnosis, especially if other systemic symptoms are present.