Foot Conditions A-Z
Blisters
Nearly everyone gets blisters from time to time. Whether they form on the hands from hard work, or whether they form on the feet from shoes or just going barefooted, blisters are an aggravation, and a potential gateway to more serious conditions if left unattended. Here's how foot blisters happen and how to prevent them.
Causes
When the outer layer of skin (epidermis) is subjected to repeated contact friction or shear forces (shear is a tearing process in the skin caused by tissue layers moving in opposing directions), a blister typically results. The friction or shear forces cause tears in the second and third layers of the skin, and pressure forces fluid into the open spaces. Fluid fills up the open spaces in the deeper layers of the skin, while the top layer remains intact. In situations where blood vessels in the skin also break, the blood drains along with the fluid, forming what are often called "blood blisters."
Blisters on the feet typically result from repetitive stress to exposed areas, particularly those that protrude or are raised, such as bunions and hammer toes, and on normal weight-bearing areas (pressure points).
The main culprit in a foot blister is an improperly fitted shoe or boot. Sometimes the design—for example, a too narrow toe box, a too wide heel area, raised seams in the shoe or boot lining--can lead to blisters even when shoes and boots are properly fitted.
Blistering is more frequent and more severe when the feet get wet, which softens the skin, making it much more vulnerable to the friction and shear forces that produce blisters. Most friction blisters tend to form in the heel area, where friction from movement of the heel causes the skin to tear.
Blisters also are commonly found:
- on the sides of the big toe and the fifth (“pinky”) toe, when the toe box of the shoes or boots “squeeze” the forefoot
- on the bottom of the toes, where friction from toe off (the final stage of the running gait, where the toes propel the runner forward as the foot is pushed off from the ground) occurs
- on the tops and tips of the toes in situations such as hammer toes, where the feet or toes have changed shape due to other issues
- on the tops of the toes, from raised seams in socks
- on the sides of the heels, when the heel area of the shoe or boot rubs and causes friction
Prevention and Treatment
To prevent blisters, IPFH suggests the following:
Wear only properly selected and fitted, as part of an integrated approach, padded socks with shoes with non-slip outsoles and any inserts or orthotics prescribed or recommended by a doctor or foot health professional.
Peer-reviewed, published studies have shown that wearing clinically tested padded socks can help protect against injuries to the skin/soft tissue of the foot.
Medical Considerations
In the short term, blisters can cause pain and be a nuisance, but if not addressed, they can do more damage. Infection is a danger if the blister breaks or if you deliberately break the skin (generally, it is not a good idea to puncture the blister by breaking the skin, although there are some exceptions). If the skin does break, use antibiotic ointment to help prevent infection.
One time to consider puncturing a blister is if the blister is preventing you from walking to safety when you are under threat - for example, if you are backpacking in an area that requires you to move from your current position to a safer location (during a storm, for example) and the blister is hampering your ability to walk.
Open a blister as soon as possible after it occurs, and definitely within 24 hours:
- Sterilize a needle with rubbing alcohol or by placing the needle in a flame.
- Pop the blister from the side (don’t go straight in), and don’t twist the needle.
- Make a few holes in different sides of the blister.
- Carefully squeeze out the fluid from the blister.
- Once the fluid has drained, seal the blister with a glycerin gel lubricant, apply an antibiotic ointment and cover with a bandage.
Do not pop blood blisters because they typically penetrate multiple layers of skin.
People with diabetes and / or neuropathy should never attempt to puncture or break blisters, but should see a medical professional such as a podiatrist or dermatologist for any blister-related problems.
Over the longer term, blisters can cause changes in your walking or running gait that can lead to more serious muscle, tendon, ligament and joint problems. Rarely, blisters can be a symptom of more serious conditions such as the hereditary condition, epidermolysis bullosa or erythema multiforme a hypersensitive reaction to infections or drugs that typically causes blisters on the palms of the hands, the forearms, the soles of the feet, and on the mucous membranes of the body.
Allergic reactions also can cause blisters. For example, exposure to plants such as poison ivy, poison oak and sumac often produces blisters, as does exposure to other allergens. In such cases, the blisters are often accompanied by inflammation / redness of the skin and itching.
Always talk to your doctor if you have soreness, pain, redness, swelling or other indications of foot problems that persist for more than a few days.
