Blisters: Understanding, Prevention and Treatment

13 min read

We’ve all experienced the surprise blister and the annoyance that comes with it. Make sure you get the most out of your next hiking, backpacking or paddling trip by following these steps to prevention: Proper selection of footwear and socks, keeping the feet dry, daily foot care and responding to hot spots on the feet before they have a chance to become blisters. When you’re done you will understand how to safely pop a blister and manage treatment to prevent infection.

UNDERSTANDING BLISTERS

Blisters are filled with a clear fluid drawn from blood serum or plasma. They can be filled with blood when there is damage to the underlying tissue, or with pus when there is infection. The fluid lays in a small pocket on the upper layer of the skin.

The primary causes of blisters are friction, and freezing or burning of the skin.

In outdoor adventure, blisters are caused by fire or sunburn, or the skin is frozen and blisters result. Friction is a prominent cause of blisters.

For instance, you might burn yourself tending to a campfire or using a camp stove. Sunburn can cause a second-degree burn and blistering. At the other end of the spectrum, freezing of the top two layers of skin will result in blistering. A blister forming from either cause is a serious matter.

In a perfect world, all blisters would be left intact and allowed time to heal. The entire blister roof serves as the most sterile and protective "bandage" for the damaged tissue underneath it. An intact blister roof is the best means of preventing infection.

In the case of blisters that result from frostbite or second degree burning you definitely must take every precaution and prevent breaking the blister roof.

In the case of friction blisters keeping the blister roof intact is ideal. But the practical reality is, the ideal is not always possible. Draining the blister may be the best alternative to allowing ongoing friction to tear off the blister roof. We’ll discuss a careful approach to popping the blister further down the page.

Friction blisters are most common on the hands and feet.

A RIVER BLISTER?

Friction blisters form more easily on damp skin than on dry or very wet skin. I learned this the hard way on a kayak trip down a spring run in Florida.

Paddling may cause a blister that forms between your thumb and first finger making it painful with each stroke. When kayaking the shaft of the paddle is generally always wet and a blister can develop due to your hands sliding, or due to an improper grip. Take note of hand placement - no white knuckles here - a light grip allows more air to flow through your hands, thereby reducing friction.

Blisters are easily prevented if you wear fingerless gloves, either those made for cycling or paddling. I bought a pair and I have never encountered another blister. The gloves create an extra layer of protection from repetitive movement.

Try applying an anti-blister cream (Trail Toes, Hike-Goo) or Vaseline where blisters occur. Or wear anti-blister pads under your gloves.

Soft neoprene pads also help alleviate blistered skin. The pads fit on the shaft of the paddle allowing your hands a more comfy grip.

If you plan to make any stops and hike into areas along the way, consider wearing water shoes in your kayak. But as dry feet are crucial to preventing blisters, you should keep a towel, dry socks and hiking boots in a waterproof bag for any sections you walk.

TAKE A HIKE!

Every outdoor adventurer has had a friction blister. If not attended to, they are excruciatingly painful. Particularly if that blister roof comes off. And in a damp, warm environment like that inside your hiking boot? They are very susceptible to infection. Hikers, backpackers, and endurance racers should all have an underlying fear of blisters.

It can put a real damper on your trip and delay the expected time for completion. And you don't want to be the hiker who asks your partner to stop every ½ mile so you can take a break, adjust your socks, and give your feet a rest.

A proper fit in shoes or boots, and dry socks are the key to preventing blisters. Sounds easy enough, right? Doesn't every hiker believe they've purchased the best hiking boots ever, and still ended up with a blister? Chalk it up to experience.

BOOTS

First, buy a lightweight hiking boot or shoe. It makes sense from the perspective of easing the load and allowing less wear and tear on your feet and legs. Leather boots should not be necessary unless you are hiking in cold temperatures or snow.

Choose boots that are waterproof. You'll be crossing streams, hiking in the rain, encountering mud, puddles and the like. To keep those feet of yours dry a waterproof boot is the way to go. Choose socks that wick perspiration away from the skin and boots that improve breathability. Remember, dampness is not a friend to your feet.

Your feet are unique. Study user reviews online, but make trips to brick and mortar stores, try on several pairs of boots. Test them out. Experiment. Move around in them like you move when walking, hiking, and climbing.

Squat, lunge, get up on your toes and down on your heels. Jump. How do your feet feel? Boots should fit like a glove but remember you may be wearing two pairs of socks. Bring your (clean) pair or set of socks with you when trying on boots.

SOCKS

Sock liners are a focal point of discussion among hikers, backpackers, and endurance racers. The evidence indicates they can decrease the incidence of blisters. (i)

A good sock liner of synthetic fabric will wick moisture away, allowing the feet to breathe. You want a snug fit. They should not bunch up, wrinkle or roll over on themselves. Toe socks further decrease the risk of blisters at the toes and wick moisture. Take a look at the Injinji brand.

Select an excellent top sock to wear over your liner socks.

Because of its thermal qualities wool - merino wool is preferred - may be the best solution for cold temperatures. But wool retains moisture. A wool-synthetic combination or a synthetic fabric will wick moisture away more effectively. That should be your primary consideration in warmer temperatures.

Cotton is a non-starter.

Always have a second pair of socks or a second set of socks in your backpack. They weigh little, and the first pair is worthless should it become wet.

PREVENTION

You’ve learned now how to get blisters. What about how NOT to get blisters? Your first goal is prevention. And that has a lot to do with experience.

But why not let our hard-won experience at least reduce the number of steps you have to take along the stony path called learning the hard way?

Most of the students in our Wilderness First Aid class are outdoor leaders. And the key to success for all is practicing leadership that is oriented to prevention. So, let me relate some history that has real meaning if you are leading groups.

In 1914, at the beginning of WWI, the British military suffered 134 casualties for every one thousand soldiers. That is the number of injuries from one narrow, specific cause - trench foot. By 1918, the number of casualties from trench foot was down to less than 4 for every one thousand soldiers.

The explanation for this was found entirely in the increased discipline imposed upon troops by their officers. A heightened discipline brought to the daily practice of foot care. Simple.

Hot spots. If you prevent hot spots, you prevent blisters. Simple.

The Five Stages of Blister Development

For outdoor adventure leaders leading multiple-day trips, the daily discipline of examining and caring for the feet is essential. Especially in the initial days of a trip. Taking breaks. Getting the boots and socks off to air dry the feet. Examining the feet for irritated areas, finding those hot spots - almost before they start. Immediate attention upon recognition of the problem. Stopping them in their tracks.

THE STEPS TO TAKE BEFORE YOU STEP OUT

  • Practice makes perfect. Put on your socks, put your feet in your boots, lace up and enjoy the day. Wear them at home, to the grocery store, walk your dog, wear them around. If you have a treadmill, think of it as your hike for the day. Consider wearing them only indoors the first day. You'll have a greater chance of success returning them if they haven't been outside. But toughen up those feet and ensure you are on the road to blister prevention, making any adjustments before you hit the trail.

  • Lace your boots tight enough to support your foot but not to the point of cutting off circulation. If you have ankle boots, a proper lacing technique will ensure your ankles are stable and protected as well.

  • Be sure toenails are trimmed, and you’re not experiencing an ingrown toenail before setting off on a hike. That little discomfort will compromise the way your foot lands with each step. It will affect your gait and increase the chance of developing the dreaded blister.

  • We’re always finding uses for duct tape. It can come in handy for hiking too. It has the advantage of that nice smooth surface. Place duct tape on any rough seams inside the boot or shoe. Many hikers use duct tape at the first sign of a hotspot. It may be applied directly to the foot or toes as another layer of protection. Do Not apply tape of any kind to an already formed blister.

  • Engo patches are a blister prevention product. They come in a variety of sizes and are applied to the interior surface of the shoe. They limit friction against the areas of your foot most vulnerable to blisters, and rarely need to be replaced.

  • Kinesiology Tape (KT Tape) comes in pre-cut lengths and has earned high praise as a means of preventing blisters. Fixomull Stretch Tape and Cover-Roll Stretch Tape are similar products. (ii) There are excellent YouTube videos to help you with the correct strategy for using these products. Do Not apply tape to an already formed blister.

  • If your hiking boots have lost some support or don’t fit quite as snug as they did when new, try purchasing a pair of insoles. Besides adding comfort, your foot will not slide as much inside the boot.

  • If you find your leather boots are rubbing, remove the laces and pull the tongue of the boot back. Apply a small amount of mink oil to the inner leather that is causing you issues. Massage the oil in, to soften the leather.

  • On non-leather hiking boots, knead the offending area that is causing any discomfort using a hard object - a rolling pin or closed pocket knife. The kneading action should help loosen the material and smooth any bulges.

  • There are quite a few anti-friction creams on the market. The cream acts as an anti-chafing agent, it protects from friction and increases elasticity. It nourishes and moisturizes the skin.

  • Talcum powder, once touted as a remedy in keeping feet dry, seems to be on the outs as newer and better products have entered the market. Traditional powders absorb moisture, but remain on your foot and clump due to soaking up the moisture. A well-reviewed product that avoids this is 2Toms Blister Powder.

BLISTER TREATMENT

As discussed earlier, if you don’t have to pop a blister, don’t! It’s Mother Nature’s means to “heal thyself.” The fluid-filled blister pads and protects the delicate tissue beneath. It creates a perfect, sterile environment for healing.

Continuing friction in the closed compartment of a boot will inevitably tear away the roof of a fluid-filled blister. This creates a soft tissue wound in the dark, damp, warm environment of the boot that is very susceptible to infection.

In this case, the best of the bad decisions is to drain the fluid and keep the blister roof intact. (iii) And protected from further friction.

Consider buying a commercial blister kit (they are inexpensive) or designing your own. Or, buy a kit and then adjust its contents to meet your unique circumstance. At a minimum blister kits will include:

  • 2nd Skin Blister Dressings

  • Adhesive

  • Antibiotic Ointment

  • Antiseptic Towelettes

  • Assorted Bandages

  • Foam Pressure Pads

  • Gel Skin Pads

  • Lubricant

  • Moleskin or Molefoam

  • Needle Or Scalpel Blade

  • Povidone (Betadine) Wipes

  • Scissors

  • Tape

(Do you have an idea you can contribute to this list? Everyone will benefit from hearing a unique solution that didn’t occur to them before. Let us know in the comments below.)

Bandaging a wound on the foot, whether a blister or anything else, is problematic. The feet perspire in the closed compartment of the boot and bandages roll over, wrinkle and become unstuck.

A product that combats this tendency is tincture of benzoin. It dries the surface of the skin so that bandages adhere more successfully. Apply it to your foot, let it dry until tacky, then place the dressing of your choice over it.

Tincture of Benzoin toughens the surface of the skin and can offer some protection from friction to skin that is not already blistered. It acts as a shield or second layer of skin.

When the need arises to pop a formed blister:

  • Clean your hands.

  • Clean the surface of the skin on and around the blister. Best practice is soap and water and then an antiseptic wipe.

  • Sterilize the needle, scissors or scalpel blade using a wipe or povidone iodine. I know you have heard of using a flame for this purpose, but it's problematic. The methods we suggest are more reliable. And safer for you. You're less likely to burn your fingers.

  • At the edge of the blister use one of the following methods to make a small opening. Pierce with a needle. Or make a small cut with scissors. Or make a small incision with the scalpel blade. Small means - about a 1/4 of an inch. Smaller than that will work.

  • I know everyone has heard the advice to use a needle many times. Scissors or a scalpel blade are a better choice. You can more easily make an effective opening. And the scalpel blade has the advantage that it is already sterile.

  • Gentle pressure on the top of the blister is enough to drain out the fluid.

  • Clean and dry the surface of the skin on and around the blister roof - again!

  • Cut a piece of moleskin (or molefoam) half an inch larger than the blister. Cut a “donut” hole a bit larger than the blister in the middle of the moleskin. Adhere the moleskin to the healthy area of skin adjacent to the blister. This is where tincture of benzoin comes into play. Do not adhere the moleskin to the blister roof itself.

  • When the moleskin is secured in place, you can apply an antibiotic cream to the blister. Then cover the moleskin (or molefoam) donut with sterile gauze.

  • Secure this all in place with duct tape. Other medical tapes will do, but duct tape has the advantage of a very smooth surface and will minimize further friction in the boot.

  • Monitor for infection. Remember, the whole purpose of this approach is to keep the blister roof intact, protected from additional friction, and preserve the delicate tissue in a sterile environment while healing. Blisters heal over a period of 7 or more days.

Additional Resources: Two experts in this field for whom I have great respect are John Vonhof and Rebecca Rushton. John made an early contribution to understanding these issues with his book Fixing Your Feet. Look for the most recent edition published in 2018 and check out his website at fixingyourfeet.com. Rebecca Rushton is a podiatrist in Australia whose website blisterprevention.com.au is a fantastic resource of in-depth understanding around the issue of foot care and prevention of foot problems.

Nancy Ferri and her husband are recently retired and avid campers. They enjoy hiking, kayaking and bicycling in the great outdoors and plan to hit the road this summer to enjoy some longer adventures throughout the U.S.

Footnotes:

(i) Knapik JJ1, Hamlet MP, Thompson KJ, Jones BH. Influence of boot-sock systems on frequency and severity of foot blisters. Mil Med. 1996 Oct;161(10):594-8.
https://www.ncbi.nlm.nih.gov/pubmed/8918120

(ii) Hoffman MD1. Etiological Foundation for Practical Strategies to Prevent Exercise-Related Foot Blisters. Curr Sports Med Rep. 2016 Sep-Oct;15(5):330-5. doi: 10.1249/JSR.0000000000000297.
https://www.ncbi.nlm.nih.gov/pubmed/27618242

(iii) Cortese TA, Fukuyama K, Epstein W, Sulzberger MB. Treatment of Friction Blisters: An Experimental Study. Arch Dermatol. 1968;97(6):717–721. doi:10.1001/archderm.1968.01610120107016
https://jamanetwork.com/journals/jamadermatology/article-abstract/530644#