Allergic Reaction: This is often the most common cause of intermittent swelling around the eyes, typically due to allergic rhinitis or an allergic reaction to substances like pollen, dust mites, or pet dander. Symptoms can include itchy, watery eyes, and swelling of the eyelids.

Blepharitis: An inflammation of the eyelids that can cause swelling, redness, and itching. It's often associated with skin conditions like acne or eczema.
Conjunctivitis: Also known as pink eye, this is an infection or inflammation of the outer membrane of the eyeball and the inner eyelid. It can cause redness, itching, and swelling of the eyes.
Sinusitis: Inflammation or infection of the sinuses can lead to swelling around the eyes due to the proximity of the sinuses to the orbital area.

Orbital Cellulitis: A serious infection of the tissues surrounding the eye, which can cause swelling, redness, and pain. It requires prompt medical attention to prevent serious complications.
Angioedema: A condition characterized by the rapid swelling of the dermis, subcutaneous tissue, mucosa, and submucosal tissues. It can be life-threatening if it involves the airways.
Thyroid Eye Disease: Associated with Graves' disease, this condition can cause swelling of the tissues around the eye, including the eyelids, and can lead to serious complications if not treated.

Wegener's Granulomatosis: A rare autoimmune disorder that can cause inflammation of the blood vessels, including those around the eyes, leading to swelling and other symptoms.
Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the eyes, leading to swelling and other ocular symptoms.
Amyloidosis: A group of diseases that result from the abnormal accumulation of amyloid proteins in various tissues, which can rarely cause swelling around the eyes.