Thanks for asking the query,Fluid filled blisters
in the lower lip are usually seen in viral infections certainly herpes
infection. Herpes is usually a acute viral condition in which itchy blisters
are formed that spread rapidly and bursting with scratching to infect the new areas rapidly. In later stages ulcerations can be seen in the mouth.
Consult your family Physician for an easy diagnosis and appropriate drugs.
Maintain a good oral hygiene
take lukewarm saline gargles.