While many blisters heal on their own, WebMD recommends a home draining procedure to help large, painful blisters heal faster. This procedure involves sterilizing a needle with rubbing alcohol, gently puncturing the edge of the blister and pushing the fluid toward the hole to drain it out. Once drained, it is important to wash the area with soap and water and apply antibiotic ointment and a clean, dry bandage.
If a blister is small and not too painful, Mayo Clinic recommends keeping it intact, as the skin covering the blister provides a barrier to outside bacteria, reducing the risk of infection and promoting healthy healing. To absorb excess moisture while allowing oxygen to reach the wound, small blisters should be covered with adhesive bandages and large blisters should be covered with porous gauze pads. For those with diabetes or circulation issues, the risk of infection is greater, so consulting a doctor before proceeding with home treatment measures is advised.
The U.S. National Library of Medicine lists several possible causes of blisters, including allergic reactions, chicken pox, herpes simplex, contact dermatitis, eczema, autoimmune disorders such as pemphigus, and skin diseases such as dermatitis herpetiformis. WebMD lists a number of injuries that can cause blisters, including spider bites and burns from heat or chemicals.