Epsom salt
Epsom salt consists primarily of magnesium sulfate and some other minerals. It is a compound that functions like a powerful anti-inflammatory agent [6] that can help treat blood blisters. It helps reduce redness, swelling, and accumulation of fluid.
Mix 1 teaspoon of epsom salt in 1 cup of warm water until it is completely dissolved. You can use the saline solution to thoroughly rinse the blister and the skin around it. Do this two to three times every day until the blister heals completely.