Friction blisters result when fluid accumulates under the skin as a direct cause of one, several, or all of the following risk contributors:

1. pressure
2. shearing forces
3. moisture
4. heat

Blistering is something that likely happens to everyone at some point in their lives on their hands or their feet. It can be a very uncomfortable experience and virtually any type of footgear can cause a blister on the feet or ankles if not fitted properly.

Friction blister care progressed rapidly with the introduction of acrylic wicking fiber technology in socks and non-prescription topical antiperspirants. Several good studies have given us the scientific evidence to recommend socks and antiperspirants as proven preventive steps to avoid friction blisters.
Some other helpful ideas to prevent friction blisters:

1.  The acrylic sock performs better if it is a double layer sock system.

2.  Regularly apply topical antiperspirants to the skin of the feet and ankles and between the toes.

3.  Have your feet professionally fitted for shoes and boots of proper length, width, and volume to eliminate potential pressure points over boney prominences or toes.

4.  A footbed can provide an efficient interface between the foot and the shoe, resulting in less foot motion within the shoe/boot. Excessive motion of the foot within the shoe or boot is one of the most common causes of friction blisters.

5.  Baby, talcum, and antifungal powders can be used to dry out the internal environment in the shoe and possibly reduce friction.

6.  Petroleum jelly, body glide, bag balm, and various other slippery products have helped active people reduce the amount of friction the foot or boot can cause to the foot or the toes.

7.  Tape, moleskin, blister block, and various hydro gels are available for prophylaxis (prevention), or can be placed over a blister that is forming.

8.  Shoe and boot dryers are available for individuals who demand daily use of their footgear, but develop a lot of perspiration during the day.

If you do develop a friction blister, you have two options. Your first option is to lance it or puncture it with a metallic object that has been boiled or subjected to flame. This treatment presents the obvious potential for bacterial infection; it is recommended that a covering be placed over the opening. Antibiotic ointments and creams have been advocated as further measures to be taken against infection. Cleansing of the area with soap and water prior to the application of the bandage/band aid is recommended.

The other option is to leave it intact and wait for it to dissipate. In my opinion, this option is not good for an individual who is still engaged in activity, such as finishing the last few miles of a long hike or run. As the blister enlarges, it creates more friction and space restriction, compounding a bad situation.
If you have diabetes or any other disease that decreases sensation in the feet, you are at particular risk for the development of friction blisters. Regular screening exams with your podiatrist are a must.