BLISTERS: THEIR CARE AND PREVENTION

Blisters are a common problem for those trying to start a new hobby, sport or job requiring motions never required of them.  We all have had blisters.  They usually are worse early in the sporting season and during times of intense training or activity.  Blisters may just be a fact of life for some, but for those willing to take a little time, they can be prevented.

Blisters arise when the shearing forces applied to our skin exceeds the resting tensile strength of the various bonded layers of our skin thus causing these layers to separate and move.  When pressure and friction are applied to skin under motion, blisters are created.  The space created fills with fluid that normally bathes our tissues with nutrients and protective factors.  When our skin is damaged or injured, this fluid seeps out of our capillaries and starts working to repair the damage done.  This fluid also acts as a cushion, filling the newly created space while protecting surrounding tissues from incurring further injury.

Blisters occur in areas of maximal surface motion and shearing force first.  They usually present as "hotspots" on our hands or feet.  If sensed early and allowed to heal or "cool-down", these hotspots can become calluses in place of becoming blisters.  Within six hours of damage, blistered skin begins to recover.  Within 48 hours, new tissue is being formed.  Complete healing usually occurs within five days when allowed to heal without further insult or injury. Blisters, once formed, are usually treated with antibiotic ointments, protective cushioning, and time.  The best treatment, however, will always be avoiding their formation all together, and the key to avoiding blisters is prevention.

There are several ways to help prevent blister formation.  Try to keep your skin, or "hotspots", cool and dry.  (Be aware that heat and moisture both contribute to and accelerate blister formation.)  When considering your feet, wear properly fitted shoes along with two pairs of socks.  The innermost layer should be thin and of a fine weave while the outer layer should be standard, well-fitting tube socks.  (Remember cotton traps moisture so a polyester inner sock may be better.)  This allows the friction to occur between the socks rather than between the sock material and your skin.  Use foot powders, moleskin, and Second Skin to reduce shearing forces.  Other blister care products new to the market include Band-Aid Blister Block, Dr. Scholl's Cushion Blister Treatment, Body Guard Skin Protection Sheets, Dr. Scholl's Moleskin Plus, Dr. Scholl's Molefoam, and Spenco 2nd Skin Blister Pads.  (All of these products were reviewed in the April 2001 issue of Backpacker magazine.)  Generic athletic tape can also be used and offers equal or better protection than these products when used properly.  When using athletic tape, extend the boundaries of the tape 1/4 to 1/2 inch beyond the blistered area to assure the tape stays in place.  A thin film of lubricant can also be applied over the tape to further reduce friction to blister prone areas.  Be aware of "hotspots" as they develop and treat them early.  With a little bit of effort, blisters can be avoided. 

If a blister is formed and it is over 2cm, drain it using a sterile technique.  To properly drain a blister: 1) Clean the area with soap and water, alcohol, or an antiseptic towelette; then dry thoroughly.  2) Sterilize a needle by either holding it over a flame until it is red hot or boil it in water for 2-3 minutes before using it.  3) Puncture the bottom edge of the blister in such a way as to allow gravity to help drain the fluid.  Massage the surface of the blister to help push the fluid out, taking care not to rupture the overlying skin further.  Keep the roof of the blister intact as this will act as an anatomical barrier and help callus formation.  4) Finally, apply an antibiotic ointment to help prevent infection and cover with a sterile dressing of your choice.

James Scherer, M.D.
Arkansas Children's Hospital
Sports Medicine Plus