If it is herpes, then applying aciclovir cream should help, but you should start doing this when your lips start to tingle - don't wait till they swell and blister. Taking aciclovir tablets ...

"Particularly swollen lips may indicate an allergic reaction ... Camp tells us. "Sores or blisters may indicate an infection ...

Aphthous ulcers are round or swollen in nature ... can also lead to rashes and blisters. Even measles can trigger formation of rashes inside the mouth. ALSO READ: Mouth ulcers: What are the ...