Hi.. Can understand your concern.. As per your complain swelling and bruising of the lips after injury occurs as a result of trauma leading to injury to soft tissues leading inflammation and rupture of blood vessels and accumulation of blood and inflammatory exudate can lead to swelling and bruising or blackish discolouration can be due to blood accumulation in soft tissues.. You should do cold compresses over the lip to reduce swelling.. For pain you can give Brufen syrup 5ml twice daily.. In case if there are open lacerations then a short course of antibiotics has to be given to prevent infecions like Amoxil syrup (containing amoxicillin and should e given only if your child is not allergic) to prevent infection. Application of an antibiotic ointment over the open laceration should be done to avoid infection.. In case of pain application of numbing gel can be done over the lip but precaution should be taken not to numb a large area as after numbing the kid can accidentally bite the lip.. Once the swelling reduces and healing begins alternate warm and cold compresses will help in faster healing.. Hope this information helps.. Thanks and regards.. Dr. Honey Nandwani Arora..