Hi, Perioral dermatitis
is due to drying of lips and is most commonly due to seasonal change or due to bit nutritional deficiency
. So do not worry about the same. You can apply any good bland moisturizing cream without any fragrance in it. Eat a lot of fruits and green leafy vegetable. Improve your daily schedule and do some light exercises. Do not sun expose to higher side. use a good sunscreen lotion also.