Suggest Remedy For Red Lining Around Vaginal Lips

I have a red lining around the vaginal lips. It is only red there and not inside. I am very familiar with the symptoms of a yeast infection and vaginitis and I do not have that. I have no discharge, smell, or itchiness. It feels a bit sore and it is a bright red. I have had no exposure to bacteria and do not use any type of fragrance product. I've been under a lot of stress, could that be it?