Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern.... As per your complain in case if there is dryness or chapping of lips due to weather change and the upper lip sore has been relieved using Vaseline then it is not a cold sore and it is CHELITIS caused due to dryness of lips which can cause inflammation and itching.. You need not to worry and apply thick coat of Petroleum jelly like Vaseline over the lips as it will lubricate the lips as well as help in locking the moisture.. Lip balm containing bees wax will also have the similar effect like vaseline.. You can also apply steroid based ointments like Hydrocortisone 1% over the bump for reducing itching and inflammation should be used only for a few days and not frequently and for months.. Apply aloevera gel as it has lubricating as well as antibacterial and antifungal properties.. Do not suck or lick your lips as it further adds up to dryness by evaporating moisture from lips.. Cover your lips with a scarf while going out in cold to avoid exposure of lips to excessive cold.. If still there is no improvement consult a DERMATOLOGIST and get evaluated for other possible causes like herpes causing cold sores.. Hope this information helps.. If you find the answer helpful please give me a Five Star Review and click on found the answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora..