The skin on both sides of the mouth is dry and cracked and red, which may be caused by physiological factors, stomatitis, contact lipitis and other factors. 1. Physiological factors: dry weather and less water, and go out without wearing a mask, the mouth area for a long time by the cold wind stimulation, will lead to the sides of the mouth peeling cracked red, eliminating the above triggers, can be improved on their own. 2. Keratitis: it may be related to infection, trauma, allergy, vitamin deficiency and other factors, which can lead to the two sides of the mouth and the lip area to appear dry, cracked and red, and in severe cases, there will be edema, vesiculation, oozing. 3. Contact Lipitis: Contact with certain cosmetics, contact with dental materials may cause contact lipitis, which can lead to skinning, cracking and redness on both sides of the mouth. And the lip area will also appear extensive swelling, lip elasticity deterioration, and in severe cases will lead to skin lesions erosion oozing. If the skin on both sides of the mouth is dry, cracked and red, and physiological factors are ruled out, accompanied by other obvious discomfort, it is recommended to consult a doctor for appropriate examination and treatment.