I have developed, on a few occasions, small fluid filled blisters inside my mouth. On the inside side of the lips, on the cheek walls, and at the back of my gum line, but on the wall of the cheek. These are soft fluid filled blisters that come in one blisters or a small group. They come quickly, within 15 minutes and last for about 3 hours-5 hours. Then they break or deflate and go away until the next occurrence. I have had this happen several times over the last few months. There is a white line that encircles the blistering area.
The vesicles are not on my tongue. They aren't outside the mouth like an HSV-1 virus outbreak. I have never been diagnosed with anything STD related before, but I am sexually active and not always as safe as I could be/should be.
The blistering area is usually in a field about the size of an american nickel or quarter. The blisters start as pin sized and inflate with fluid until the are about 1/8th of an inch and raised and then they burst. They NEVER cause pain unless I scratch the blister causing a wound.
They are full of clear fluid. Never pus or mucous or anything colored. If I tear the top of to drain it it sometimes bleeds slightly.
I have high quality pictures I took today if you would like to see the pictures.