A blood blister is a small vesicle filled with fluid or rather blood that appears under the skin after rubbing, a pinch, a burn or sunburn. Blood blisters on the fingers are usually painful and can obstruct certain movements or activities, especially if they are big.
If the blood blister is small, do not burst it. Since it can slow the healing process or may cause an infection.
Instead, clean it with water and further treat it with an antibiotic cream. Also, protect it with a sterile dressing.
If the blister bursts of its own, do not to remove the skin but disinfect and dress the wound.
I think blisters should touch and it should be left in order to cure. Blisters can heal by its own with a week or two. Btw, you can wash your blood blister area, apply antibiotic ointment to heal quickly.