Hi , this may be due to your mask being too tight. Have you tried any of the products that may help prevent sores? Some products that may help include: RemZzz’s mask liners, Gecko nasal pad, MaskMate sealer and lubricant, and SoreSpot CPAP Skin Protectors. Hopefully, these will help prevent the sores. Keep us posted. Warmly, Kristin (SleepApnea.Sleep-Disorders.net Team Member)