Lupus mouth sores are red with a white ring around them. White lines may extend out from the sores. Ulcers can form anywhere in your mouth, but they often appear on the roof of the mouth, the lining of the cheeks, the gums, and the lips. In your nose, you'll find ulcers on the wall that separates your two nostrils, called the septum. The ulcers might be painless, or they may hurt.