Hello, As per your complaint, swollen knot on the roof of mouth secondary to coughing, sneezing, and fever that seems to be like a viral infection or upper respiratory tract infection can be a pyogenic granuloma, an inflamed minor salivary gland known as an adenoma. You should consult an ENT physician and get evaluated, and a thorough clinical evaluation can help in diagnosis and treatment can be planned accordingly. As of now you can do warm saline gargles, do steam inhalations. Take an Acetaminophen for fever. Avoid spicy food and maintain good oral hygiene. Drink plenty of warm water. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Honey Arora