DEAR DOCTOR K:
I wore a new pair of hiking boots on my vacation and now have several painful blisters on my feet. What’s the best way to treat them?
It sounds like you have friction blisters. A friction blister is a soft pocket of raised skin filled with clear fluid, caused by irritation from continuous rubbing or pressure.
The irritation — in your case caused by new hiking boots — slightly damages the skin. The uppermost layer of skin separates from the layer beneath, and fluid accumulates in the space that’s left. the blister also contains blood, it is called a blood blister. Here is an illustration of a friction blister:
Friction blisters typically drain on their own within days. A new layer of skin forms beneath the blister and eventually the blistered skin peels away. As a result, friction blisters don’t generally require any special treatment.
Be sure to keep the blisters clean and dry. And also keep them intact: The skin provides a natural protection against infection. Do not try to drain the blister or pierce or cut away the overlying skin. In doing so, you can allow bacteria to get into the wound and cause an infection.
If a blister breaks on its own, wash the area with soap and water. Then gently pat it dry, use an antibacterial ointment and cover it with a bandage. Do this every time you get the blister wet (from swimming or from bathing) and at least once a day.
If pressure or friction continues in the same area, the blister may last longer. Sometimes it is impossible to avoid further irritation (for example, if your new hiking boots were the only shoes you brought on your vacation). In this case, protect the blister with a more heavy-duty sterile bandage.
Continued friction may cause the blister to break open, ooze fluid and become infected. See your doctor immediately if you think you have an infection, notice significant redness or drainage that is not clear fluid, or develop a fever.
To prevent friction blisters in the future, wear shoes that fit well. That means the shoe should not be tight anywhere and should not slide up and down your heel when you walk. Wear socks that have good elastic and don’t tend to bunch up. And try to keep your feet dry.
When you buy new shoes or boots, break them in over a few weeks before taking long walks and hikes. It’s rare for brand-new shoes or boots to fit your feet well under conditions of maximum stress.
Like you, I learned this the hard way. I bought a pair of new boots before taking a several-day hike in the New England mountains. By the second day, I had two fierce friction blisters, one on each foot. The trip was considerably less fun after that.