What Is a Friction Blister? Here's What to Know—And How to Treat It
Doctors say most hand and foot blisters can be managed with simple, at-home treatments.
If you've ever developed a raised, fluid-filled bubble on your hand after raking leaves or on your heel while breaking in new shoes, you've had a friction blister. And the question that often crosses people's minds is how to deal with that injury: Is it better to pop the bubble or leave it alone?
Here's what doctors say you should know about friction blisters and their causes, how to treat them, and what you can do to prevent them.
What is a friction blister, exactly?
A friction blister is nothing more than a repetitive injury—skin rubbing against an object.
While the resulting blister may be painful, it's usually something you can easily manage at home. Of course, some blistering may be more extensive, and you may need to see a doctor if it becomes infected, according to the Cleveland Clinic.
What causes friction blisters?
These blisters develop due to pressure and sheer force on the affected area of skin, often when the skin is moist or damp, studies show. In one small study published in the journal Skin Research & Technology, researchers looked at what would happen to a wet foot placed under strain in a controlled laboratory setting compared with its dry counterpart. Wet feet were more prone to developing blisters, in line with earlier studies, the authors noted.
These various factors cause the skin's outer surface to separate from the underlying layer of cells known as the stratum spinosum. When that happens, the injured area quickly fills with clear, plasma-like fluid, forming a bubble below the skin's outermost layer. Sometimes, if the separation between skin layers goes deeper, the area can fill with blood, per McGill University's Office of Science and Society.
"Friction, pressure, and the inability to wick moisture away from your skin—those are your three real culprits of why blisters will form," Fred H Brennan, Jr., assistant director of the University of South Florida-BayCare family medicine and sports medicine programs in Clearwater, Florida, tells Health.
Who usually gets friction blisters?
Almost anyone can get a friction blister. That said, it can be a particular problem for athletes, members of the military, and people in certain occupations. Folks tend to sustain these injuries while running, walking, hiking, or using sports equipment or tools.
Dermatologists tell Health the most common sites for friction blisters are:
Anyone who's ever worn a pair of uncomfortable shoes knows that friction blisters can occur anywhere on the feet "where their shoes are rubbing them in the wrong way," Lisa Chipps, MD, a Los Angeles-based, board-certified dermatologist, tells Health. She says patients usually don't come to the doctor for a friction blister "because they know what caused it."
Sometimes weightlifters get blisters on their hands, which eventually turn into calluses, Dr. Chipps points out. She's also seen blisters on windsurfers' hands from the friction of gripping the boom.
Having studied friction blisters in competitive athletes and members of the military, Dr. Brennan cites certain risk factors associated with these injuries. They include:
- Moisture (such as sweaty feet or hands)
- Poor-fitting footwear
- Carrying heavy loads
- Having poorly controlled diabetes
With foot blisters, lack of conditioning may also play a role, says Dr. Brennan. "Your feet have to be broken in; they have to be hardened, if you will, so there's some adaptation that happens to the skin of your feet," he explains.
How can you treat a friction blister?
In most cases, you can manage a friction blister at home. Just keep in mind that it can take a week or two for your blister to heal, according to the American Academy of Dermatology Association (AAD). Here's what you can to help the process along:
Don't pop the bubble
In general, if the fluid-filled bubble is still intact, leave it alone. "It's sterile inside, and you've got your own natural bandage in the bubble," explains Dr. Chipps. "The skin of the bubble is protecting the wound underneath from getting any bacteria or anything inside," which could lead to infection.
Clean and protect an open wound
Wash the area with soap and water, then dab with Vaseline or Aquaphor before covering it. Petroleum jelly acts as a barrier against infection, Dr. Brennan explains. Another option: Cover the wound with a hydrocolloid bandage, which helps with healing and provides a "friction-proof barrier," he adds. The AAD also suggests applying a bandage loosely so that the absorbent pad is slightly raised above the injured area.
If you must pop the bubble, do it safely
When a blister is large, painful, or in a place that interferes with daily activities, clean the area and use a needle sterilized with rubbing alcohol to gently prick the side of the blister, draining the fluid beneath the skin. Leave that flap of skin in place to protect the area. And then clean and protect the area (as described above).
If you're left with a flap of dry, dead skin, snip with caution
"You should just carefully remove that dead piece of skin once it's already popped on its own," says Dr. Brennan. Mayo Clinic advises cutting away the dead skin with sterilized tweezers or scissors before applying more ointment and a bandage.
Pad the area
To ease friction and pressure, affix a doughnut-shaped moleskin or other cushioning pad so that the hole surrounds the blister. Then cover the area with a bandage.
Most of the time, blisters resolve on their own, says Dr. Brennan. But if your wound becomes more painful, red, or smelly, it's probably infected—and time to see a doctor.
How can you prevent friction blisters?
While most blisters heal in a week or two (assuming you're not repeatedly aggravating the area), it's best to avoid blistering in the first place. Here are some things to try:
- Make sure your shoes or boots fit properly.
- Break in your footwear before extended use.
- Wear moisture-wicking socks. If one pair doesn't keep you dry, AAD suggests doubling up.
- Wear gloves if you're getting hand blisters from sporting activities or manual labor.
If you've been indoors all winter, Dr. Brennan suggests taking it easy on the first beautiful day of spring. It's best to increase your hiking volume gradually so your feet will adapt to the load they're carrying, he says.
The Mayo Clinic suggests dusting the inside of your socks with talcum powder. And while that may be helpful for a short outing, Dr. Brennan says applying powder, petroleum jelly, or moisturizer to your feet before an endurance event can actually make foot blistering worse.
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