A burning sensation in the mouth and nose can be caused by a dry environment, infectious factors, physical irritation, allergies and other factors. 1. environmental dryness: dry outside air, or due to vomiting, diarrhea, etc. caused by the loss of body fluids, may lead to the mouth and nose with the feeling of fire. 2. Infectious factors: nasal mucosal inflammation will cause mucosal congestion and swelling, as well as inflammation of the mouth and tongue, mouth ulcers, etc., can also cause the mouth and nose have a burning feeling. 3. Physical stimulation: for example, eating too spicy food or inhaling irritating chemical gases can also cause the mouth and nose to feel on fire. 4. Allergic factors: allergies or allergic asthma, allergic rhinitis, etc., may also cause a burning sensation in the mouth and nose. There may be other reasons for the burning sensation in the mouth and nose, and you need to go to the hospital in time for examination and clear cause of the disease and follow the doctor’s instructions.