STYLETHREAD -- LET'S TALK SHOP!

I don't know what it's called, but I know exactly what you are talking about.  Try using a q-tip to apply some Neosporin (get the "plus pain relief" kind if you can) to the blister area and cover with a band aid.  You don't need to sleep in a band aid IMO, but wear one during the day.  Wear some shoes that don't rub directly on the blister area.  (Usually with me, flip flops work great because they don't touch the areas where I get blisters.)  The Neosporin is great because it makes them less painful. They'll heal on their own, usually in a few days.  Don't walk a long distance in the same shoes again until the blisters heal.  HTH!

No real description of the fluid according to WebMD. http://my.webmd.com/hw/health_guide_atoz/aa67373.asp

I've had those & have popped them w/a clean pin after swabbing the area w/alcohol.  Generally, it'll heal & dry up on its own.  Be sure to keep it clean & let it air out @ night.