VERONIQUE HAUSCHILD
Injury Prevention Program
U.S. Army Public Health Center (Provisional)
Aberdeen Proving Ground, Maryland
Most of us have experienced the pain of a friction blister. These injuries form when an object, such as a sock, shoe or strap, is repeatedly moved across a part of the body with enough force to cause the layers of skin to release heat. The heat causes redness and a separation, or cleft, between the outermost layer of the skin and rest of the layers. The cleft then fills with fluid, causing a raised area on the skin.
Blisters typically form on the toes, feet and ankles, but they can also occur on the hands or other places where there is repeated rubbing, such as the torso from the straps of a heavy backpack. Because these injuries often only cause discomfort and don’t require medical treatment, they are sometimes described as “just a blister.” Some blisters, however, came become temporarily debilitating for Soldiers, forcing them to restrict certain activities and limit physical training. In some cases, friction blisters develop into infections that require antibiotics and medical treatment. As one of the most common injuries among Soldiers, friction blisters can have a notable adverse impact on military readiness.
Activities such as marching and running are the most common causes of blisters in the military. A recent review of injuries associated with marching or hiking showed heavy load carriage increases the risk of foot blisters. While Soldiers may not be able to avoid some activities that put them at risk for developing blisters, there are precautions they can take to minimize the likelihood of developing one and/or reduce the severity of any that do develop.
Studies provide evidence that some people may have a higher risk of developing blisters. For example, having no foot arch or flat feet, or being of an ethnicity other than African American, can increase your risk of getting a blister. While these factors cannot be changed, others that increase the risk of blisters can be modified. The U.S. Army Public Health Center (Provisional) offers the following tactics that might be helpful in reducing the risk of developing a blister:
Adaptation
To help your skin become more resistant:
- Slowly increase the duration and intensity of blister-causing activities.
- Use the same boots/shoes, gloves or load weight as you increase activity.
Socks
Keep skin dry:
- Synthetic socks — made from acrylic, nylon or polyester, rather than cotton — that ventilate and wick moisture away from the feet are recommended, especially during long-distance marching or running.
- Some people advocate wearing a double layer of synthetic socks since a second layer stops the first from rubbing against the skin. Others, however, prefer a single-layer loop-stitched sock, as less heat is generated than with two layers. Scientific evidence does not clearly indicate which is best. This may vary with individual risk factors.
Other options to consider include:
Shoes
Minimize contact between the foot and shoe:
- Make sure toes do not touch the end of the shoe while walking. Consider a wide toe box with room for toes to wiggle.
- Purchase shoes later in the day since feet may swell half a size larger throughout the day or after an activity.
- Do not leave shoes/boots on radiators or near heaters since this can cause them to shrink and the seams to protrude.
Taping and skin coverings
- Certain skin coverings have been shown to help absorb friction during movement, which can reduce blister occurrence or severity.
- Zinc oxide tape has been anecdotally reported in running communities to prevent blisters from forming or minimizing further injury to an existing blister. Other products referred to as “blister plasters” will expand in response to friction and protect the area from blisters forming or getting worse.
Insoles
- A closed-cell neoprene insole was found to reduce the incidence of blisters in U.S. Coast Guard recruits.
- Anecdotal reports suggest properly fitted insoles can reduce blisters, but ill-fitting insoles can increase them.
Coatings
- Some athletes advocate using products such as petroleum jelly to reduce friction and prevent chafing and blisters.
- While prior studies suggested antiperspirants may reduce blisters, there is a risk of skin irritation, so it is not specifically recommended.
There is limited scientific evidence validating the effectiveness of most blister-preventing tactics among large populations. What works for some may not work for others, so it’s up the individual Soldier to determine their own best practices to avoid the pesky, painful blister.
FYI
The Mayo Clinic recommends keeping a blister intact to help reduce the risk of infection. However, if a blister becomes too painful and medical help is not available, the following measures can be taken to drain it:
- Wash your hands and the blister with soap and warm water.
- Swab the blister with iodine.
- Sterilize a clean, sharp needle by wiping it with rubbing alcohol.
- Use the needle to puncture the blister. Aim for several spots near the blister's edge. Let the fluid drain, but leave the overlying skin in place.
- Apply an ointment (Vaseline, Plastibase, other) to the blister and cover it with a nonstick gauze bandage. If a rash appears, stop using the ointment.
- Change the dressing every day. Apply more ointment and a bandage.