Updated: Aug 13, 2018
Blisters are a common problem for runners. Not only can they become an annoyance and painful while running, if not treated appropriately, they can cause worse skin problems, including open sores and infections.
Why do blisters occur?
Blisters occur where there is friction or shear force. For runners, they often present along the toes and heels. Wearing new shoes, or improperly sized shoes can increase the risk for developing blisters. Other factors contributing to blister formation include increased heat and moisture (e.g. sweat), as well as the presence of foot deformities, as these tend to be more prominent areas that rub inside shoes while running (5).
When it comes to treating blisters, the protocol depends on how they present. Below are three different scenarios on how I would, personally, treat different types of blisters.
1. Intact, small blister without signs of infection
I typically recommend leaving the blister alone and not popping or de-roofing it. If you peel off the blistered tissue, the underlying skin is new and fragile, so it is better to leave the outer blistered skin layer intact and allow it to dry up and fall off on its own.
While in shoes, the area should be protected. A donut pad (made from moleskin, felt, or foam) can be placed around the blister. Make sure the padding is thick enough so that the blister is no longer rubbing once in a shoe. Then, the blister can be covered with a second protective layer. Moleskin, paper tape, or a bandaid can be used for this.
If the blister ends up popping or breaking, the area needs to be cleaned, antibiotic can be applied (if necessary), and the area should be covered with a bandaid or 2nd skin until it is dry and while in shoes.
2. Intact, large blister
If the blister is large and interferes with putting shoes on or participating in activities, the blister can be punctured (after it is cleaned with an antiseptic) to allow for the fluid to drain. This should be done with sterile instrumentation, and the area should be covered afterwards until the blister dries up and while wearing shoes.
3. Blister with blood or purulence
If the fluid is not clear, it is important to evaluate the area further. The blister should be cleaned with an antiseptic, then de-roofed completely. The area should be cleaned thoroughly and protected until dry and while wearing shoes. The care for these blisters should be handled by a healthcare professional using sterile instrumentation. If the exudate appears to be discolored, it may be cultured, and you may need a short course of antibiotics.
**Note on dressings: If you are using bandaids or other more occlusive dressings and they are causing the underlying tissue to become too wet and macerated (skin appears white and wrinkly), take the dressing off while at home to allow the foot to air-dry (as long as you don’t have any open wounds). Then, while in shoes, try using other less occlusive dressings, such as gauze.
1. Shoe gear
Wearing properly fit shoes can help prevent the occurrence of blisters.
The shoes should be slowly broken in, as well. Wearing new shoes for extended periods of time can also result in blister formation.
2. Moleskin and padding materials
If you have any foot deformities that cause bony prominences, such as the tops of the toes with hammertoes or around the big toe joint with bunions, you can place padding (i.e. moleskin, foam, felt) inside the shoe where your hot spots are to help prevent blisters from occurring.
3. Paper tape
I have personally not used paper tape to prevent blisters from forming; however, a recent article published in 2016 showed a 40% reduction in blister formation amongst ultramarathon runners who used paper tape on their feet in blister prone and randomly selected areas (4). So, it may be worth a try!
4. Reducing heat and moisture
These two factors may be the most difficult to control, yet many companies are targeting them by creating products that claim to help with blister prevention. There are a number of different sweat-wicking socks and antiperspirants available, but the research behind them appears to be limited and inconsistent.
Socks: Herring & Richie performed two studies on acrylic versus cotton socks in runners. In their 1990 study, they found acrylic socks to be superior to cotton socks with regards to blister formation; however, when they used a more generic cushioned sock in their 1993 study, there was no difference in the incidence of blister formation between the two different socks (1,2).
Antiperspirants: A 1995 study showed that the use of an antiperspirant with emollients did not improve sweat accumulation or blister incidence (6). A later study, done on military cadets, compared an antiperspirant (20% aluminum chloride solution) alone against a placebo and found a reduction in blister formation in the antiperspirant group; however, that same group also reported more skin irritation (3). Therefore, when looking for an antiperspirant, try to find a product that will both reduce sweat and prevent blisters from forming but will also not dry your feet out too much and cause a skin rash.
As you can see, it may be difficult to prevent blisters from happening. The best thing to do is to wear properly fit shoes, protect hot spot areas, and try to decrease the amount of heat and moisture in your shoes by changing out of them once you’re done with your run or race. When you do get a blister, treat it immediately so it doesn’t worsen, and luckily, there are now several products available that will allow you to continue training even in the presence of foot blisters.
DISCLAIMER: The above information is meant for educational purposes only and should not be construed as medical advice. Please consult the doctor, or your own healthcare professional, should you have questions or concerns related to your health.
1. Herring, K. M., & Richie Jr, D. H. (1990). Friction blisters and sock fiber composition. A double-blind study. Journal of the American podiatric medical association, 80(2), 63-71.
2. Herring, K. M., & Richie, D. H. (1993). Comparison of cotton and acrylic socks using a generic cushion sole design for runners. JOURNAL-AMERICAN PODIATRIC MEDICAL ASSOCIATION, 83, 515-515.
3. Knapik, J. J., Reynolds, K., & Barson, J. (1998). Influence of an antiperspirant on foot blister incidence during cross-country hiking. Journal of the American Academy of Dermatology, 39(2), 202-206.
4. Lipman, G. S., Sharp, L. J., Christensen, M., Phillips, C., DiTullio, A., Dalton, A., ... & Krabak, B. J. (2016). Paper tape prevents foot blisters: a randomized prevention trial assessing paper tape in endurance distances II (Pre-TAPED II). Clinical Journal of Sport Medicine, 26(5), 362-368.
5. Mailler-Savage, E. A., & Adams, B. B. (2006). Skin manifestations of running. Journal of the American Academy of Dermatology, 55(2), 290-301.
6. Reynolds, K., Darrigrand, A., Roberts, D., Knapik, J., Pollard, J., Duplantis, K., & Jones, B. (1995). Effects of an antiperspirant with emollients on foot-sweat accumulation and blister formation while walking in the heat. Journal of the American Academy of Dermatology, 33(4), 626-630.