Hi.. Can understand your concern.. As per your complain the chapping and sores over the lips can be due to cold sores which is caused by a virus known as Herpes Simplex Virus 1. The beginning of the infection can be pain,burning and tingling around the mouth at times swelling of the lips and slowly the small sores or ulcers are erupted over the lips.. It can be accompanied with dryness and chapped lips.. The sores can be persistent for a few days and can then can resolve and there can be relapsed episodes of sores.. The chapped lips and formation of blister can be due to excessive sun exposure leading to formation of sun blister,dry lips and swelling due to inflammation.. It can also be due to sharing of lipsticks or chap sticks with other individuals causing bacterial infection on lips.. I would suggest you to consult a dermatologist and get evaluated and in case if it is herpes antiviral topical application and oral intake of antivirals like Acyclovir can prevent the further outbreaks as the antiviral drugs can not treat the infection and can only prevent outbreaks and recurrences.. Apply thick coat of petroleum jelly or aloevera gel for dryness and chapping of lips. In case it is due to sun burn ice packs on lips can help.. Apply 1% hydrocortizone cream over the lips to reduce inflammation and swelling.. Apply cooling gels containing aloe vera over the lips as it will provide relief.. For dryness and chapping apply aloe vera gel can be applied. Avoid petroleum jelly as it can absorb more heat and can further add up to irritation.. Apply SPF 15 containing lip balm when going into sun and also avoid direct sun exposure of the lips to sun by keeping them covered.. In case of bacterial infection antiseptic cream and oral antibiotics can help.. Apply thick coat of petroleum jelly after cleaning the lips to maintain lubrication and prevent dryness irritation.. Yo can also apply aloe vera gel olive oil or coconut oil.. Hope this information helps.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.