High intensity activities can cause blisters on the feet due to rubbing material on the affected area.  Usually the foot wear is new and ill fitting.  Sweating may increase the friction over pressure areas in the shoe/boot.  A high arch or cavus foot may be more susceptible to shoe rub and blister formation on the top of the foot as well as over the metatarsal head area.


Treatment:
1.    Clean blister and surrounding area with isopropyl alcohol or other sterilization agent.
2.    Sterilize needle with open flame or isopropyl alcohol.
3.    Aspirate blister with a sterile needle.  Avoid penetrating with needle into non-painful skin.  
4.    Remove needle and gently press blister to force out liquid from blister “sack”.  
5.    Leave skin over affected area of blister.  This will act as a biological dressing and decrease tenderness until new skin forms and matures in a few days.
6.    Clean area with pavidone-iodine, isopropyl alcohol or other sterilization agent and cover with moleskin or small bandage.


Field/operations conditions

1.     Pop blister if large and painful.  Clean affected area if conditions permit.  Place moleskin or duct tape over area and continue with hiking/mission.

Mole Skin
     Moleskin is used to prevent or treat friction injuries of the feet. In the case of a blister, the moleskin is cut with a hole in the center so the fabric does not adhere to the blister directly. The thickness of the surrounding moleskin protects the blister from further friction. If you cannot cut a hole in the moleskin and you don’t have time or equipment to cut the hole, just place the moleskin over the blister.


Personal Experience
     From Army basic training, AIT, field operations, Sapper Leader Course and desert deployments in the Middle East I have had the thrill of dealing with blisters for years.  I’ve had blisters on top of blisters, lost my large toe nails due to carrying heavy loads for hours and miles.  Had blisters in between almost every toe, across the entire ball of the foot, on the bottom of the heel and half dollar size on the back of my heel, all at the same time.
     One of the most effective ways of dealing with blisters is prevention.  When all else fails, I have used knee high stockings and moisture wicking socks such as polypropylene next to the skin and wool socks as a second layer.  The stockings and polypropylene are slick and keep your feet from rubbing on your socks and interior of your boots.  The stockings and polypropylene also help keep your feet warm during cold conditions and help to transport sweat away from the foot and to the sock.  Remember to wear wool socks.  Cotton retains moisture and increases the coefficient of friction.  Change socks often to keep them clean and dry. Wool retains insulating properties and will maintain heat even when wet.  Be sure to use moleskin on previous blisters.  This will aid in the prevention of new blisters forming in the same spots.
     I used isopropyl alcohol to clean the affected area then dipped my needle into the alcohol or used a lighter and heated the needle to a glowing red.  Then I lanced the blister and squeezed out the liquid.  I placed a band aid on small blisters or used a medical pad such as a 2x2 on the blister and attached with tape around the edges.  In some cases I wrapped the tape around my foot to aid in keeping the dressing in place.


Foot Blisters

Giel Boles, Giel S. Boles