Allergic Rhinitis: This condition is characterized by an allergic reaction to airborne allergens, leading to inflammation and swelling in the nasal passages and surrounding areas, including the inner canthus.

Blepharitis: Inflammation of the eyelids can cause puffiness around the eyes, including the inner canthus, due to meibomian gland dysfunction or other factors.
Sinusitis: Infection or inflammation of the sinuses can lead to swelling and puffiness in the facial area, including the inner canthus, due to the proximity of the sinuses to the eyes.
Dacryocystitis: Inflammation of the lacrimal sac can cause swelling and puffiness in the inner canthus area, often accompanied by discharge or tearing.

Orbital Cellulitis: A serious infection of the tissues surrounding the eye, which can cause severe swelling, including puffiness of the inner canthus, and requires prompt medical attention to prevent serious complications.
Thyroid Ophthalmopathy: Although less common, thyroid eye disease can cause swelling and puffiness around the eyes, including the inner canthus, due to autoimmune inflammation.
Basal Cell Carcinoma or Other Tumors: Rarely, a tumor in the medial canthal area can cause localized swelling and puffiness.

Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can cause inflammation and damage to various parts of the body, including the eyes, leading to puffiness and other symptoms.
Sarcoidosis: Another rare condition that can cause inflammation in various parts of the body, including the eyes, leading to symptoms such as puffiness in the inner canthus area.