Dental Abscess or Infection: This is often the most common cause of facial swelling and pain, especially if the swelling is localized and accompanied by dental symptoms such as toothache or sensitivity. The burning discomfort could be due to the infection spreading to the surrounding tissues.

Sinusitis: Inflammation of the sinuses can cause facial swelling and pain, particularly if the maxillary sinuses are involved. The burning discomfort might be due to the pressure and congestion associated with sinusitis.
Cellulitis: A bacterial skin infection that can cause swelling, redness, and pain. The burning sensation could be part of the inflammatory response.
Allergic Reaction: An allergic reaction to an insect bite, food, or other allergen could cause facial swelling and discomfort, including a burning sensation.

Ludwig's Angina: A severe infection of the tissues in the neck, which can cause swelling and pain. It's a medical emergency because it can lead to airway obstruction.
Cavernous Sinus Thrombosis: A rare but potentially life-threatening condition where a blood clot forms in the cavernous sinus, leading to facial pain, swelling, and other neurological symptoms.
Temporal Arteritis (Giant Cell Arteritis): Inflammation of the blood vessels, particularly those in the head, which can cause facial pain, swelling, and visual disturbances. It's a medical emergency because it can lead to blindness if not treated promptly.

Sarcoidosis: A condition where inflammatory cells form in various parts of the body, including the face, leading to swelling and discomfort.
Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can cause inflammation of the blood vessels, leading to facial pain, swelling, and other systemic symptoms.
Neoplastic Conditions: Various types of cancer, such as lymphoma or squamous cell carcinoma, could cause facial swelling and discomfort, although these would be less common presentations.