Hi, I can understand your concern for sudden severe dryness and redness in the corners of mouth. There can be multiple possibilities of the problem and without pictures or personal examination it would be pretty difficult to comment. Even then there can be possibility of herpes or simple these bumps can be eruptions due to friction and contact with cosmetics also. Apply plane petrolatum gelly for the dryness and antibiotic cream such as fucidin cream over the red eruptions. Take care.