How to Heal a Blister

Whether it’s from wearing too-tight shoes, an allergic reaction, a skin infection, or something else, chances are you’ve experienced blisters first-hand. And while they are primarily short-lived and relatively benign, a blister can still be quite painful. Here’s what you need to know about blisters, the best way to treat them (or if you even should), and how to prevent them from showing up in the first place.

A blister is an often-painful skin condition that can occur when fluid fills a space that forms between layers of the skin. Because this fluid is typically clear, it can also be known as a water blister, although a blister can also be filled with blood or pus, if infected.

Quick anatomy lesson: Your skin contains three layers, including the outermost epidermis, the underlying dermis and the hypodermis, or subcutaneous layer of fat. A blister forms between the epidermis and dermis as a fluid-filled sac, according to the Cleveland Clinic, and is the result of injury or damage to the skin.

While most blisters come from repetitive friction (like walking in shoes without socks), they can also be due to other issues. Knowing what’s caused the blister can help you determine the best way to treat it.

“Blisters may form from a variety of reasons, including friction, trauma, swelling, autoimmune diseases, diabetes, or from medications,” notes Ivy Lee, M.D., medical director of Direct Dermatology in Pasadena, CA. Let’s take a closer look at some common causes of blisters.

• Allergic reactions: These blisters can occur as a result of allergic contact dermatitis, caused by a reaction to a chemical or poison (like poison ivy).

• Autoimmune Disease: Blisters can be a result of an autoimmune issue like pemphigus. This and other autoimmune blistering diseases occur when the body mistakenly attacks healthy tissue, causing blisters on the skin and mucous membranes. [AJC1] [AS2] These diseases can also create a variety of symptoms throughout the body, including fever, pain, or fatigue.

• Diabetes: While relatively uncommon, people with diabetes can develop blisters on their fingers, hands, toes, feet, legs, and forearms, according to the American Diabetes Association. They’re generally painless and go away on their own.

• Friction or repetitive rubbing: “Friction blisters result from chronic pressure or friction on the skin, such as from wearing ill-fitting shoes. They’re most common on the palms and soles,” says Vicky Zhen Ren, M.D., a dermatologist and assistant professor at Baylor College of Medicine in Houston.

• Trauma: This can often be the result of burns or scalds, as the body’s way of protecting the underlying skin from infection.

Most blisters that occur from friction are filled with a clear fluid in the upper layers of the skin. They often occur on the hands, from doing repetitive tasks like shoveling) or on the feet or ankles (from wearing shoes that rub or chafe).

Blood blisters can occur when something pinches your skin, according to the Cleveland Clinic. If this occurs, blood flows into the area from broken blood vessels, pooling beneath the skin and forming a blister.

Heat blisters can result from sunburn or second-degree burns, and can appear anywhere on the body that has been burned.

Infected blister will fill with a milky white pus and may be painful or itchy.

So should you pop a blister, or just let it be? “It’s ideal to let a blister heal and reabsorb on its own,” says Dr. Lee. If it’s not bothering you too badly, she adds, a blister “can serve as its own bandage.” Most blisters will heal on their own in about one or two weeks. To help speed healing, the American Academy of Dermatology Association recommends the following:

• Loosely cover the blister with a bandage, making sure that the middle of the bandage is raised over the top of the blister (not pressing down on it).

• If the blister is in an area exposed to a lot of pressure (such as the bottom of your foot), cut some padding such as moleskin into a donut shape with a hole in the middle, and place it around the blister. Secure the padding in place with a bandage.

• Be sure to follow proper wound care, keeping the area around the blister clean and dry. Apply petroleum jelly or an antibiotic ointment to expedite healing, says Dr. Lee, and change the bandage daily. If possible, avoid activities that can cause further irritation.

Blisters that are a result of burns or infections should almost always be left alone to heal. A large friction blister that is too painful to walk on, however, may be carefully drained and treated, says Dr. Lee.

• Clean the blister site with rubbing alcohol and sterilize a small needle.

• Use the needle to carefully pierce one edge of the blister and create a small drainage hole, allowing the fluid to drain out. “Do not remove the roof of the blister as that can serve as a natural bandage,” says Dr. Lee.

• Once it’s drained, wash the area of the blister with soap and water and apply petroleum jelly or an antibiotic ointment.

• Keep the area clean and covered; and change the bandage daily. If possible, avoid activities that can cause further irritation.

In most cases, a blister is an annoying but fairly harmless inconvenience that might put you off from a long walk or a pair of dressy shoes. But there are times when medical intervention is required, says Dr. Zhen Ren. These can include the following:

• Blisters in sensitive areas may be a sign of a sexually transmitted disease like genital herpes.

• Increasing redness, swelling, warmth or purulent drainage (a thick white, yellow or brown fluid oozing from the blister) may be a sign of a bacterial infection.

• Large or recurrent blisters appearing elsewhere on your body can indicate an infection.

• Worsening pain in the area can indicate trauma or infection.

• Talk to your doctor about any of these conditions to get prompt treatment, speed healing and prevent a potential infection from getting worse.

Blisters aren’t likely to be a long-term concern, but they’re no fun to deal with. So consider the following steps to avoid their appearance in the first place.

• Avoid known allergens or irritants. These can cause your skin to become irritated and more prone to blisters.

• Keep your feet dry. “Try to reduce moisture in the affected area during activity,” notes Dr. Lee. A foot powder can help prevent sweaty feet from developing blisters.

• Take a break. If you have a repetitive task like shoveling snow or gardening to do, take frequent breaks from the triggering activity, especially if you sense an area getting irritated.

• Use protective padding. If you’re going to be out for a long hike or know you are prone to blisters on your hands when doing yard work, be prepared. Get extra-cushy socks, wear work gloves, and consider putting a bandage on the area that is often affected.

• Wear properly fitting shoes and socks. “You want to minimize the points of friction and trauma to the skin as best you can,” says Dr. Lee. Remember that the next time you slip on a new pair of strappy sandals or shove your foot into your shoe without a sock.

Bottom Line

Blisters are often a minor annoyance that can be treated at home (or simply left alone to heal by itself). But if you notice signs of infection or other symptoms that might indicate another health condition, talk to your doctor and seek medical attention.