When blisters are afoot

Grant Lipman, MD, an emergency medicine physician, sees to a blister during a race in the Altacama Desert, Chile.

Most of us are not fond of our feet, perhaps because we constrict them with shoes and transform them into playing fields for that most common of foot problems: the blister.

And while most of us would prefer not to think about blisters, Grant Lipman, MD, an emergency medicine physician at Stanford Hospital & Clinics, believes they are the most common medical problem we experience when we venture outdoors and into the wild. Lipman has become a nationally known blister expert, in fact, and recently co-authored an entire chapter on blisters for Wilderness Medicine, compiled by his Stanford colleague Paul Auerbach, MD.

An estimated 10 million Americans go out hiking each year and at least one in seven will develop the classic blister caused by friction between foot, sock and shoe. The numbers also show that less experienced hikers are more likely to develop a blister. 

What to do, then, to prevent the pain, possible infection and disruptions to activities that blisters can incur? Blisters develop when the upper layer of the skin is rubbed so much that it begins to separate from the lower layers. Smooth things out by filing down calluses and trimming toenails, Lipman said.

Be defensive by using paper-like tape on typical problem points or where you've blistered previously-between the toes, for example, or the back of the heel. Pads or padding, Lipman said, can change the way your foot fits into a shoe and abet blister formation. Make sure that your socks and shoes fit properly. Wearing two pairs of socks, a thin one inside a thicker one, can help create a protective layer.

"I pop any blister that hurts," said Lipman, "except if it's filled with blood. That blood indicates a deep injury to the dermis." Clean the prong of a safety pin with an alcohol-soaked pad and then puncture the blister; use the pad to wipe it clean. Cover the blister with paper tape, then with another layer of stretchy tape, preferably made of cotton cloth.

Lipman said the best way to limit blister development and damage is take protective or repair measures as soon as you feel pain. "Even if you're in a rainstorm or a snowstorm, stop," he said. "That hot spot is a sign that you're starting to delaminate those layers of skin."

And once you've treated your blisters, he said, try to stay off your feet. Unless, of course, you've got a hike to finish.